National Library of Energy BETA

Sample records for rpd-sc iot o-2

  1. IoT Interoperability at Bosch

    Broader source: Energy.gov (indexed) [DOE]

    Acquire d S oftwa re Innova tions , 2008 Bus ine s s proce s s ma na ge me nt Cloud-ba s e d IoT s olutions Acquiring P ros ys t (a nnounce d Fe brua ry 2015) P...

  2. Open Services for IoT Cloud Applications in the Future Internet

    E-Print Network [OSTI]

    Barnaghi, Payam M.

    -- Internet of Things (IoT) is an emerging area that not only requires development of infrastructure but alsoOpen Services for IoT Cloud Applications in the Future Internet *Martin Serrano1 , Hoan Nguyen M-domain) applications. In the race of designing the IoT as part of the Future Internet architecture, academic and ICT

  3. IOT beam simulations with the PIC code WARP

    E-Print Network [OSTI]

    Anlage, Steven

    IOT beam simulations with the PIC code WARP Kiersten Ruisard Institute for Research in Electronics for comparison with CST, Michelle Kiersten Ruisard, UMD 33/12/2014 #12;· PIC code for accelerator applications/12/2014 Introduction to WARP Geometry packages: Transverse (X-Y) slice Axisymmetric R-Z Full 3D · Standard PIC mode

  4. Hardware Design Techniques for Securing and Synthesizing Resource-Constrained IoT Systems

    E-Print Network [OSTI]

    Wendt, James Bradley

    2015-01-01

    The Internet of Things . . . . . . . . .in World Forum on Internet of Things (WF- IoT), pp. P13. M.Industrial Internet and Internet of Things | GE Software. ”

  5. Internet of Things Introduction to Internet ofThings (IoT)

    E-Print Network [OSTI]

    Roussos, George

    Internet of Things Peng Du #12;Content Introduction to Internet ofThings (IoT) Challenges IPv6 / 6LoWPAN ROLL #12;What is Internet of Things (IoT) Internet TCP/IP Things Criteria #12;Elements A brief idea what Internet ofThings is and why it is interesting to us Appreciated IPv6 is one

  6. 2O 2O2O 2OAn Executive's Guide to the Criteria for Performance Excellence

    E-Print Network [OSTI]

    #12;BALDRIGE 2O 2O2O 2OAn Executive's Guide to the Criteria for Performance Excellence That Used the Criteria to Become U.S. Role Models #12;Baldrige Performance Excellence Program National, Millie Glick, Harry Hertz, Scott Kurtz, and Jeff Lucas. Book design and illustrations by Capitol

  7. Health Monitoring and Management Using Internet-of-Things (IoT) Sensing with Cloud-based

    E-Print Network [OSTI]

    Sharma, Gaurav

    Health Monitoring and Management Using Internet-of-Things (IoT) Sensing with Cloud-based Processing enabled by the Internet of Things (IoT), smart and connected health care is a particularly important one the gathering of rich information indicative of our physical and mental health. Captured on a continual basis

  8. Insecurity of An Anonymous Authentication For Privacy-preserving IoT Target-driven Applications

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    -Jun Lin and Lin Sun November 28, 2013 Abstract: The Internet of Things (IoT) will be formed by smart that their protocol is insecure. The adversary can cheat the data collectors by impersonating a legitimate user. Key, two roles are defined for participant nodes: Users and Data Collectors. Users are the nodes

  9. A comprehensive and lightweight security architecture to secure the IoT

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    and water management, or environmental sensing in a smart city environment. Security in such scenarios firstly reviews security and operational goals in an IoT scenario inspired in a smart city environment will be deployed in multiple scenarios including smart homes, healthcare, or smart cities. In each

  10. Demo Abstract: Supporting Interoperability of Things in IoT Systems

    E-Print Network [OSTI]

    Mei, Alessandro

    : lastname@di.uniroma1.it. ABSTRACT The Internet of the future will be of things: Large scale IoT systems in the framework of EU FP7 Lighthouse project IoT-A: Internet of Things--Architecture (http the term Internet of Things was coined in '99 in the context of a supply chain management [1], a variety

  11. Aura: An IoT based Cloud Infrastructure for Localized Mobile Computation Outsourcing

    E-Print Network [OSTI]

    Bedwell, David M.

    , the emergence of Internet-of-Things (IoT) devices has caused a paradigm shift in computing and communication. Io, Internet of things, MapReduce I. INTRODUCTION The emergence of cloud computing has created a ma- jor shift long distances through the public Internet when using such clouds. For highly interactive and time

  12. Report on the First International Workshop on Personal Data Analytics in the Internet of Things (PDA@IOT 2014)

    E-Print Network [OSTI]

    Palpanas, Themis

    billion daily-use objects, while its economic value will reach $14.4 trillion dollars, spread across all to the individual, especially when they are seen as the new oil of the global economy6 , PDA@IOT focus on how

  13. Create the Internet of Your Things The Internet of Things (IoT) is here today, and it begins

    E-Print Network [OSTI]

    Chaudhuri, Surajit

    Create the Internet of Your Things The Internet of Things (IoT) is here today, and it begins you create the Internet of Your Things, beginning with what matters most to your business. Using if you qualify for a Quick Start consultation. Transform Your Business With the Internet of Your Things

  14. A Hybrid Semantic Matchmaker for IoT Services Gilbert Cassar, Payam Barnaghi, Wei Wang, Klaus Moessner

    E-Print Network [OSTI]

    Wei, Wang

    and service oriented computing paradigm in Internet of Things research has recently received significant recommendation, composition, and provisioning in Internet of Things. However, scalability of the current de- vices and resources is one of the main promises of the Internet of Things (IoT) [1]. Service

  15. Journal of Solid State Chemistry 177 (2004) 39954000 Microwave dielectric properties of BaO2CeO2nTiO2 ceramics

    E-Print Network [OSTI]

    Osnabrück, Universität

    2004-01-01

    ÀnTiO2 ceramics H. Sreemoolanadhana,1 , M.T. Sebastiana,Ã, R. Ratheeshb,2 , R. Blachnikb , M. Woehleckec , B. Schneiderc , M. Neumannc , P. Mohanand a Regional Research Laboratory, Ceramic Technology online 6 October 2004 Abstract The BaO­2CeO2­nTiO2 ceramics with n ¼ 3; 4 and 5 have been prepared

  16. Rate-dependent morphology of Li2O2 growth in Li-O2 batteries

    E-Print Network [OSTI]

    Horstmann, B; Mitchell, R; Bessler, W G; Shao-Horn, Y; Bazant, M Z

    2013-01-01

    Compact solid discharge products enable energy storage devices with high gravimetric and volumetric energy densities, but solid deposits on active surfaces can disturb charge transport and induce mechanical stress. In this Letter we develop a nanoscale continuum model for the growth of Li2O2 crystals in lithium-oxygen batteries with organic electrolytes, based on a theory of electrochemical non-equilibrium thermodynamics originally applied to Li-ion batteries. As in the case of lithium insertion in phase-separating LiFePO4 nanoparticles, the theory predicts a transition from complex to uniform morphologies of Li2O2 with increasing current. Discrete particle growth at low discharge rates becomes suppressed at high rates, resulting in a film of electronically insulating Li2O2 that limits cell performance. We predict that the transition between these surface growth modes occurs at current densities close to the exchange current density of the cathode reaction, consistent with experimental observations.

  17. Shipboard Atmospheric O2 Measurements in the Equatorial Pacific

    E-Print Network [OSTI]

    Stephens, Britton B.

    of equatorial O2 and CO2 outgassing in these models, the lack of a seasonal marine O2 rectifier in these models of DIC and preformed nutrients and the strong air-sea heat fluxes lead to a net outgassing of O2 and CO2

  18. High-Performance ZrO2-Coated LiNiO2 Cathode Material Jaephil Cho,a,

    E-Print Network [OSTI]

    Park, Byungwoo

    O2 has a high-fracture toughness of 8-12 MPa m.16 Experimental LiNiO2 powders were prepared from lattice structure. Since metal oxides with low ductility initiate mechanically induced micro- cracks

  19. DOI: 10.1002/adma.200601830 RuO2 Nanowires and RuO2/TiO2 Core/Shell Nanowires: From

    E-Print Network [OSTI]

    Wang, Zhong L.

    the energy loss owing to the difference in refractive index between Ta2O5 and SiO2. Following the successful Research and Engineering (DDR&E), the Defense Advanced Research Project Agency (N66001

  20. SnO2 atomic layer deposition on ZrO2 and Al nanoparticles: Pathway to enhanced thermite materials

    E-Print Network [OSTI]

    George, Steven M.

    SnO2 atomic layer deposition on ZrO2 and Al nanoparticles: Pathway to enhanced thermite materials J of Colorado, Boulder, CO 80309-0414, United States Available online 1 June 2005 Abstract Thermite mixtures with traditional thermite mixtures. One technique to create thermite mixtures with improved contact is to deposit

  1. Tropospheric O 3 from photolysis of O 2

    E-Print Network [OSTI]

    Prather, Michael J

    2009-01-01

    I (NNG06GB84G) and NSF Atmospheric Chemistry (ATM-0550234).impact on global atmospheric chemistry is small, i.e. , ±photolytic rate for atmospheric chemistry is that of O 2 (J-

  2. Photocatalytic reduction of methylene blue by TiO2 nanotube arrays: effects of TiO2 crystalline phase

    E-Print Network [OSTI]

    Kang, Xiongwu; Chen, Shaowei

    2010-01-01

    arrays: effects of TiO 2 crystalline phase Xiongwu Kang •formation of well- de?ned anatase crystalline phase. Moreat 470 °C, the brookite crystalline phase also started to

  3. Effects of CeO2 Support Facets on VOx/CeO2 Catalysts in Oxidative Dehydrogenation of Methanol

    SciTech Connect (OSTI)

    Li, Yan; Wei, Zhehao; Gao, Feng; Kovarik, Libor; Peden, Charles HF; Wang, Yong

    2014-05-13

    CeO2 supports with dominating facets, i.e., low index (100), (110) and (111) facets, are prepared. The facet effects on the structure and catalytic performance of supported vanadium oxide catalysts are investigated using oxidative dehydrogenation of methanol as a model reaction. In the presence of mixed facets, Infrared and Raman characterizations demonstrate that surface vanadia species preferentially deposit on CeO2 (100) facets, presumably because of its higher surface energy. At the same surface vanadium densities, VOx species on (100) facets show better dispersion, followed by (110) and (111) facets. The VOx species on CeO2 nanorods with (110) and (100) facets display higher activity and lower apparent activation energies compared to that on CeO2 nanopolyhedras with dominating (111) facets and CeO2 nanocubes with dominating (100) facets. The higher activity for VOx/CeO2(110) might be related to the more abundant oxygen vacancies present on the (110) facets, evidenced from Raman spectroscopic measurements.

  4. Microelectronically fabricated LiCoO2/SiO2/polycrystalline-silicon power cells planarized by chemical mechanical polishing

    E-Print Network [OSTI]

    Microelectronically fabricated LiCoO2/SiO2/polycrystalline-silicon power cells planarized and characterized ultrathin solid-state thin-film power cells consisting of LiCoO2, SiO2, and polysilicon. Cells. Integrating a power unit onto a silicon chip requires the implementation of a thin-film solid-state battery

  5. On the Origin and Implications of Li$_2$O$_2$ Toroid Formation in Nonaqueous Li-O$_2$ Batteries

    E-Print Network [OSTI]

    Aetukuri, Nagaphani B; García, Jeannette M; Krupp, Leslie E; Viswanathan, Venkatasubramanian; Luntz, Alan C

    2014-01-01

    The lithium-air (Li-O$_2$) battery has received enormous attention as a possible alternative to current state-of-the-art rechargeable Li-ion batteries given their high theoretical specific energy. However, the maximum discharge capacity in nonaqueous Li-O$_2$ batteries is limited to a small fraction of its theoretical value due to the insulating nature of lithium peroxide, Li$_2$O$_2$, the battery$'$s primary discharge product. In this work, we show that the inclusion of trace amounts of electrolyte additives, such as H$_2$O, significantly improve the capacity of the Li-O$_2$ battery. These additives trigger a solution-based growth mechanism due to their solvating properties, thereby circumventing the Li$_2$O$_2$ conductivity limitation. Experimental observations and a growth model imply that this solution mechanism is responsible for Li$_2$ toroid formation. We present a general formalism describing an additive$'$s tendency to trigger the solution process, providing a rational design route for electrolytes t...

  6. Hole Trapping at Surfaces of m?ZrO2 and m?HfO2 Nanocrystals

    SciTech Connect (OSTI)

    Wolf, Matthew J.; Mckenna, Keith P.; Shlyuger, Alexander L.

    2012-12-03

    We investigate hole trapping at the most prevalent facets of monoclinic zirconia (m-ZrO2) and hafnia (m-HfO2) nanocrystals using first-principles methods. The localization of holes at surface oxygen ions is more favorable than in the bulk crystal by up to ?1 eV. This is caused mainly by the reduction of the absolute value of the electrostatic potential at the surface ions with respect to the bulk and by the significant surface distortion caused by the hole localization. The mobility of holes at surfaces is much lower than that found in the bulk and is fairly isotropic. Unlike in cubic oxides, such as MgO and CaO, we do not find a significant driving force for preferential trapping of holes at steps on the m-ZrO2 surface. These fundamental results are relevant to mechanisms of water oxidation, photocatalysis, contact charging, and photodesorption.

  7. Artificial Photosynthesis on TiO2-Passivated InP Nanopillars

    E-Print Network [OSTI]

    2015-01-01

    of TiO 2 by atomic layer deposition. The role of theseof TiO 2 by atomic layer deposition. Plane wave-densitycontaminants. 8 Atomic layer deposition (ALD) of TiO 2 was

  8. igh-dielectricshavebeenactivelypursuedtoreplaceSiO2 asgate insulatorsforsilicondevices1

    E-Print Network [OSTI]

    McEuen, Paul L.

    with advanced gate dielectrics may open a new route to advanced miniature field- effectdevices. Single gates with SiO2 dielectrics18 and electrochemical gates with an aqueous electrolyte solution obtained by annealing the devices in hydrogen exhibit S ~ 90 mV per decade. High voltage gains of up to 60

  9. Comparative studies of low-temperature watergas shift reaction over Pt=CeO2, Au=CeO2,

    E-Print Network [OSTI]

    Gulari, Erdogan

    , has shown that ceria affects in a number of catalytic reactions. Cerium oxide or Ceria (CeO2) may attention re- cently because of their catalytic activity in low temperature CO oxidation, catalytic; accepted 13 March 2003 Abstract We studied catalytic low-temperature water­gas shift (WGS) reaction over

  10. Optical properties of bismuth-doped SiO2- or GeO2-based glass core optical fibers

    E-Print Network [OSTI]

    Firstova, Elena G

    2015-01-01

    A detailed study of optical properties of bismuth-doped fibers based on SiO2 and GeO2 glasses containing no other dopants has been carried out. To provide important information about spectroscopic properties of IR bismuth-related active centers (BAC) the excitation-emission fluorescence spectra for a spectral region of 220-2000 nm have been measured. The obtained three-dimensional spectra have been presented for different host glass compositions: silicate, germanate, aluminosilicate and phosphosilicate. Energy-level configuration and main radiative transitions associated with BACs in GeO2 and SiO2 glasses have been revealed. Fluorescence lifetime analysis of the basic radiative transitions of BAC have been carried out. It has been shown that the energy-level schemes of BAC-Si and BAC-Ge (BAC associated with silicon and germanium, respectively) are similar, corresponding BAC-Ge energy levels lying 10-16% lower than those of BAC-Si. It has been determined that BAC-Si, BAC-Ge and BAC-Si, BAC-P can exist simultan...

  11. Rate-Dependent Morphology of Li2O2 Growth in Li-O2 Batteries Birger Horstmann,1, 2, 3, 4

    E-Print Network [OSTI]

    Bazant, Martin Z.

    Rate-Dependent Morphology of Li2O2 Growth in Li-O2 Batteries Birger Horstmann,1, 2, 3, 4 Betar continuum model for the growth of Li2O2 crystals in lithium-oxygen batteries with organic electrolytes-ion batteries. As in the case of lithium insertion in phase-separating LiFePO4 nanoparticles, the theory

  12. Synthesis of Na-Stabilized Nonporous tZrO2 Supports and Pt/t-ZrO2 Catalysts and Application to Water-Gas-Shift Reaction

    E-Print Network [OSTI]

    Poeppelmeier, Kenneth R.

    steam reforming,10 and epoxidation of olefins.11 ZrO2 exists primarily in three different polymorphs significantly affect the catalytic performance for chemical reactions. Ma et al. prepared t-ZrO2 using Na2CO3 catalytic performance for methanol synthesis from CO hydrogenation compared to amorphous and m-ZrO2

  13. Surface Passivation of Nanoporous TiO2 via Atomic Layer Deposition of ZrO2 for Solid-State Dye-Sensitized Solar Cell Applications

    E-Print Network [OSTI]

    Surface Passivation of Nanoporous TiO2 via Atomic Layer Deposition of ZrO2 for Solid-State Dye; ReVised Manuscript ReceiVed: August 22, 2009 We report here the utilization of atomic layer deposition to passivate surface trap states in mesoporous TiO2 nanoparticles for solid-state dye

  14. Abstract The O2 requirements for biomass pro-duction and supplying maintenance energy de-

    E-Print Network [OSTI]

    Daugulis, Andrew J.

    Abstract The O2 requirements for biomass pro- duction and supplying maintenance energy de- mands-state data. For benzene and ethylbenzene, the biomass yield on O2, YX=O2 , was estimated on a cell dry weight.022 mgO2 mg CDW­1 h­1 , respec- tively. Keywords Bioscrubber Æ BTEX Æ Maintenance energy Æ Oxygen

  15. Short communication TiO2 nanoparticles-decorated carbon nanotubes for significantly improved

    E-Print Network [OSTI]

    Short communication TiO2 nanoparticles-decorated carbon nanotubes for significantly improved to synthesize nanohybrids of anatase TiO2 nanoparticles-decorating carbon nanotubes (CNTs@TiO2). The nanohybrid a l a b s t r a c t TiO2 nanoparticles-decorated CNTs.

  16. Carbon monoxide annealed TiO2 nanotube array electrodes for efficient biosensor applications

    E-Print Network [OSTI]

    Cao, Guozhong

    Carbon monoxide annealed TiO2 nanotube array electrodes for efficient biosensor applications-grown and the O2-annealed TNT array electrodes. The improved biosensor properties of the TiO2 nanotube arrays were, particularly TiO2 nanotubes (TNT), which possess large surface areas, have been widely used as chemical sensors

  17. Anisotropic thermal transport in highly ordered TiO2 nanotube arrays Liying Guo,1

    E-Print Network [OSTI]

    Lin, Zhiqun

    Anisotropic thermal transport in highly ordered TiO2 nanotube arrays Liying Guo,1 Jun Wang,2 Zhiqun amorphous and anatase TiO2 nanotube arrays. Strong anisotropic thermal conductivity is observed: 0.617 W K-1 for amorphous TiO2 nanotube arrays. The anatase TiO2 nanotube arrays are found to have a higher and anisotropic

  18. Water, O2 and Ice in Molecular Clouds

    E-Print Network [OSTI]

    David Hollenbach; Michael J. Kaufman; Edwin A. Bergin; Gary J. Melnick

    2009-03-02

    We model the temperature and chemical structure of molecular clouds as a function of depth into the cloud, assuming a cloud of constant density n illuminated by an external FUV (6 eV < E < 13.6 eV) flux G_0 (scaling factor in multiples of the local interstellar field). Extending previous photodissociation region models, we include the freezing of species, simple grain surface chemistry, and desorption (including FUV photodesorption) of ices. We also treat the opaque cloud interior with time-dependent chemistry. Here, under certain conditions, gas phase elemental oxygen freezes out as water ice and the elemental C/O abundance ratio can exceed unity, leading to complex carbon chemistry. Gas phase H2O and O2 peak in abundance at intermediate depth into the cloud, roughly A_V~3-8 from the surface, the depth proportional to ln(G_0/n). Closer to the surface, molecules are photodissociated. Deeper into the cloud, molecules freeze to grain surfaces. At intermediate depths photodissociation rates are attenuated by dust extinction, but photodesorption prevents total freezeout. For G_0 < 500, abundances of H2O and O2 peak at values ~10^(-7), producing columns ~10^(15) per cm^2, independent of G_0 and n. The peak abundances depend primarily on the product of the photodesorption yield of water ice and the grain surface area per H nucleus. At higher values of G_0, thermal desorption of O atoms from grains enhances the gas phase H2O peak abundance and column slightly, whereas the gas phase O2 peak abundance rises to ~10^(-5) and the column to ~2x10^(16) per cm^2. We present simple analytic equations for the abundances as a function of depth which clarify the dependence on parameters. The models are applied to observations of H2O, O2, and water ice in a number of sources, including B68, NGC 2024, and Rho Oph.

  19. trans-K3[TcO2(CN)4

    SciTech Connect (OSTI)

    Chatterjee, Sayandev; Del Negro, Andrew S.; Edwards, Matthew K.; Twamley, Brendan; Krause, Jeanette A.; Bryan, Samuel A.

    2010-07-14

    The dioxotetracyanotechnetate anion, [TcO2(CN)4]3-, of the title complex has octahedral symmetry. The technetium is located on a center of inversion and is bound by two oxygen atoms and four cyano ligands. The Tc?O bond distance of 1.7721 (12) Å is consistent with double bond character. The potassium cations [located on special (1/2,0,1) and general positions] reside in octahedral or tetrahedral environments; interionic K···O and K···N interactions occur in the 2.7877 (19)-2.8598 (15) Å range.

  20. Heat Transfer between Graphene and Amorphous SiO2

    E-Print Network [OSTI]

    B. N. J. Persson; H. Ueba

    2010-07-22

    We study the heat transfer between graphene and amorphous SiO2. We include both the heat transfer from the area of real contact, and between the surfaces in the non-contact region. We consider the radiative heat transfer associated with the evanescent electromagnetic waves which exist outside of all bodies, and the heat transfer by the gas in the non-contact region. We find that the dominant contribution to the heat transfer result from the area of real contact, and the calculated value of the heat transfer coefficient is in good agreement with the value deduced from experimental data.

  1. O2Diesel Corporation formerly Dynamic Ventures | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History ViewMayo, Maryland:NPI VenturesNewSt. Louis, Minnesota:Nulato,Nyack, New Jump to:Medians |O2Diesel

  2. Compact Potentiometric O2/NOx Sensor | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum Based Fuels|Programs |ChartPresentations:UlJmately , the1 DOE Hydrogen andO2/NOx

  3. Atmospheric Pressure Chemical Vapor Deposition of High Silica SiO2-TiO2 Antireflective Thin Films for Glass Based Solar Panels

    SciTech Connect (OSTI)

    Klobukowski, Erik R; Tenhaeff, Wyatt E; McCamy, James; Harris, Caroline; Narula, Chaitanya Kumar

    2013-01-01

    The atmospheric pressure chemical vapor deposition (APCVD) of SiO2-TiO2 thin films employing [[(tBuO)3Si]2O-Ti(OiPr)2], which can be prepared from commercially available materials, results in antireflective thin films on float glass under industrially relevant manufacturing conditions. It was found that while the deposition temperature had an effect on the SiO2:TiO2 ratio, the thickness was dependent on the time of deposition. This study shows that it is possible to use APCVD employing a single source precursor containing titanium and silicon to produce thin films on float glass with high SiO2:TiO2 ratios.

  4. Faster Proton Transfer Dynamics of Water on SnO2 Compared to TiO2

    SciTech Connect (OSTI)

    Kumar, Nitin [ORNL; Kent, Paul R [ORNL; Bandura, Andrei V. [St. Petersburg State University, St. Petersburg, Russia; Kubicki, James D. [Pennsylvania State University; Wesolowski, David J [ORNL; Cole, David R [ORNL; Sofo, Jorge O. [Pennsylvania State University

    2011-01-01

    Proton jump processes in the hydration layer on the isostructural TiO2 rutile (110) and SnO2 cassiterite (110) surfaces were studied with density functional theory molecular dynamics. We find that the proton jump rate is more than three times faster on cassiterite compared with rutile. A local analysis based on the correlation between the stretching band of the O-H vibrations and the strength of H-bonds indicates that the faster proton jump activity on cassiterite is produced by a stronger H-bond formation between the surface and the hydration layer above the surface. The origin of the increased H-bond strength on cassiterite is a combined effect of stronger covalent bonding and stronger electrostatic interactions due to differences of its electronic structure. The bridging oxygens form the strongest H-bonds between the surface and the hydration layer. This higher proton jump rate is likely to affect reactivity and catalytic activity on the surface. A better understanding of its origins will enable methods to control these rates.

  5. Low Temperature Autoignition of C8H16O2 Ethyl and Methyl Esters...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Temperature Autoignition of C8H16O2 Ethyl and Methyl Esters in a Motored Engine Low Temperature Autoignition of C8H16O2 Ethyl and Methyl Esters in a Motored Engine qThe alkyl chain...

  6. Activation of a MnO2 cathode by water-stimulated Mg2+ insertion...

    Office of Scientific and Technical Information (OSTI)

    Activation of a MnO2 cathode by water-stimulated Mg2+ insertion for a magnesium ion battery Citation Details In-Document Search Title: Activation of a MnO2 cathode by...

  7. In-situ Electrical Conductivity of LixMnO2 Nanowires as a Function...

    Office of Scientific and Technical Information (OSTI)

    In-situ Electrical Conductivity of LixMnO2 Nanowires as a Function of "x" and Size Citation Details In-Document Search Title: In-situ Electrical Conductivity of LixMnO2 Nanowires...

  8. Fabrication of 3D Core-Shell Multiwalled Carbon Nanotube@RuO2...

    Office of Scientific and Technical Information (OSTI)

    Multiwalled Carbon Nanotube@RuO2 Lithium-Ion Battery Electrodes through a RuO2 Atomic Layer Deposition Process Citation Details In-Document Search Title: Fabrication of 3D...

  9. Using the Oxygen Plasma Machine 1. Turn on the O2 (g) valve on the wall.

    E-Print Network [OSTI]

    Using the Oxygen Plasma Machine 1. Turn on the O2 (g) valve on the wall. 2. Turn on the O2 inlet valve on the front of the machine just a tiny-bit ­ O2 should now be leaking through the black, chamber-right of the machine), just the Red Power Switch. 6. Turn off the O2 valve on the chamber door. At the same time, turn

  10. CO Oxidation at the Interface between Doped CeO2 and Supported Au Nanoclusters

    E-Print Network [OSTI]

    Henkelman, Graeme

    nanoclusters (NCs) supported on either CeO2 or doped (X-Ce)O2 (X = Au, Pt, Pd, Ti, Ru, Zr) show that dopingCO Oxidation at the Interface between Doped CeO2 and Supported Au Nanoclusters Hyun You Kim, we study the e ect of doping on CO oxidation catalyzed by CeO2-supported Au13 NCs and, especially, CO

  11. 6.11 Atmospheric CO2 and O2 During the Phanerozoic: Tools, Patterns, and Impacts

    E-Print Network [OSTI]

    Royer, Dana

    6.11 Atmospheric CO2 and O2 During the Phanerozoic: Tools, Patterns, and Impacts DL Royer, Wesleyan.11.2 Models for Atmospheric CO2 and O2 Estimation 251 6.11.2.1 Key Principles 251 6.11.2.2 GEOCARB Models 252.11.2.2.5 Estimates of CO2 and O2 from the GEOCARB model 254 6.11.2.3 Other Models for CO2 and O2 Reconstruction 254 6

  12. The change in oceanic O2 inventory associated with recent global warming

    E-Print Network [OSTI]

    Keeling, Ralph

    The change in oceanic O2 inventory associated with recent global warming Ralph F. Keeling, 2002 (received for review September 24, 2001) Oceans general circulation models predict that global warming may cause a decrease in the oceanic O2 inventory and an associated O2 outgassing. An independent

  13. Retrieval of global hydrogen peroxide (H2O2) profiles using ENVISAT-MIPAS

    E-Print Network [OSTI]

    Oxford, University of

    Retrieval of global hydrogen peroxide (H2O2) profiles using ENVISAT-MIPAS E. Papandrea,1,2 A2O2. We demonstrate the feasibility of profile retrievals in the range 6­35 km and obtain zonal mean), Retrieval of global hydrogen peroxide (H2O2) profiles using ENVISAT-MIPAS, Geophys. Res. Lett., 32, L14809

  14. Branched CNT@SnO2 nanorods@carbon hierarchical heterostructures for lithium ion

    E-Print Network [OSTI]

    Qi, Limin

    Branched CNT@SnO2 nanorods@carbon hierarchical heterostructures for lithium ion batteries with high used as an anode material in lithium ion batteries, the branched CNT@SnO2@C heterostructures exhibited of the 1D mesocrystalline SnO2 nanorods. Introduction Lithium ion batteries (LIBs) have become

  15. Investigation into Photoconductivity in Single CNF/TiO2-Dye Core–Shell Nanowire Devices

    E-Print Network [OSTI]

    Li, Zhuangzhi; Rochford, Caitlin; Baca, Francisco Javier A.

    2010-06-15

    A vertically aligned carbon nanofiber array coated with anatase TiO2 (CNF/TiO2) is an attractive possible replacement for the sintered TiO2 nanoparticle network in the original dye-sensitized solar cell (DSSC) design due to the potential...

  16. Exciton-like trap states limit electron mobility in TiO2 nanotubes

    E-Print Network [OSTI]

    Exciton-like trap states limit electron mobility in TiO2 nanotubes Christiaan Richter and Charles A , that low mobility in polycrystalline TiO2 nanotubes is not due to scattering from grain boundaries (electrons) be transported through an anodic TiO2 electrode, either along the length of nanotubes in the case

  17. Electromechanical properties of freestanding graphene functionalized with tin oxide (SnO2) nanoparticles

    E-Print Network [OSTI]

    Thibado, Paul M.

    -type inorganic nanocrystals formed from materials such as ZnO, TiO2, SnO2, etc.2,3 In particular, SnO2,8 Single-walled carbon nanotubes promise even more efficient conversion due to their potentially large sur carbon nanotubes by a chemical solution route.10 Nanotubes have proved difficult to work with, however

  18. Freestanding TiO2 Nanotube Arrays with Ultrahigh Aspect Ratio via Electrochemical Anodization

    E-Print Network [OSTI]

    Lin, Zhiqun

    Articles Freestanding TiO2 Nanotube Arrays with Ultrahigh Aspect Ratio via Electrochemical,5 photocatalytic,6 and solar cells.7­10 In the latter context, each individual TiO2 nanotube is perpendicular acid (HF) aqueous solution was used as electrolyte, the maximum thickness of TiO2 nanotube arrays

  19. Significantly accelerated osteoblast cell growth on aligned TiO2 nanotubes

    E-Print Network [OSTI]

    Daraio, Chiara

    Significantly accelerated osteoblast cell growth on aligned TiO2 nanotubes Seunghan Oh, Chiara: Vertically aligned yet laterally spaced nanoscale TiO2 nanotubes have been grown on Ti by anodization/propagation of the osteoblast is substantially improved by the topography of the TiO2 nanotubes with the filopodia of growing

  20. Leakage current and dielectric breakdown behavior in annealed SiO2 aerogel films

    E-Print Network [OSTI]

    Jo, Moon-Ho

    Leakage current and dielectric breakdown behavior in annealed SiO2 aerogel films Moon-Ho Jo behavior in annealed SiO2 aerogel films for intermetal dielectric applications was investigated in a metal­insulator­semiconductor structure. SiO2 aerogel films with porosities of 70% exhibited Poole­Frenkel conduction both before

  1. Electrical conductivity in Li2O2 and its role in determining capacity limitations in non-aqueous Li-O2 batteries

    E-Print Network [OSTI]

    Thygesen, Kristian

    -O2 batteries V. Viswanathan, K. S. Thygesen, J. S. Hummelshøj, J. K. Nørskov, G. Girishkumar et al limitations in non-aqueous Li-O2 batteries V. Viswanathan,1 K. S. Thygesen,2 J. S. Hummelshøj,3 J. K. Nørskov energy density battery couple. Such cells, however, show sudden death at capacities far below

  2. Systematic Modulation of Quantum (Electron) Tunneling Behavior by Atomic Layer Deposition on Nanoparticulate SnO2 and TiO2

    E-Print Network [OSTI]

    Systematic Modulation of Quantum (Electron) Tunneling Behavior by Atomic Layer Deposition were conformally created on SnO2 and TiO2 photo- electrodes via atomic layer deposition (ALD undesired, additional conduits for ET.13 In contrast, atomic layer deposition (ALD),14-19 which typically

  3. Density functional theory study of first-layer adsorption of ZrO2 and HfO2 on Ge(100)

    E-Print Network [OSTI]

    Kummel, Andrew C.

    in this manuscript), usually grown by atomic layer deposition (ALD). These oxides, under normal Ge process- ingDensity functional theory study of first-layer adsorption of ZrO2 and HfO2 on Ge(100) T.J. Grassman

  4. Charging properties of cassiterite (alfa-SnO2) surfaces

    SciTech Connect (OSTI)

    Rosenqvist, Jorgen K; Machesky, Michael L.; Vlcek, L.; Cummings, Peter T; Wesolowski, David J

    2009-01-01

    The acid-base properties of cassiterite (alfa-SnO2) surfaces at 10 50 C were studied using potentiometric titrations of powder suspensions in aqueous NaCl and RbCl media. The proton sorption isotherms exhibited common intersection points in the pH-range 4.0 to 4.5 at all conditions and the magnitude of charging was similar but not identical in NaCl and RbCl. The hydrogen bonding configuration at the oxide-water interface, obtained from classical Molecular Dynamics (MD) simulations, was analyzed in detail and the results were explicitly incorporated in calculations of protonation constants for the reactive surface sites using the revised MUSIC model. The calculations indicated that the terminal SnOH2 group is more acidic than the bridging Sn2OH group, with protonation constants (log KH) of 3.60 and 5.13 at 25 C, respectively. This is contrary to the situation on the isostructural alfa-TiO2 (rutile), apparently due to the difference in electronegativity between Ti and Sn. MD simulations and speciation calculations indicated considerable differences in the speciation of Na+ and Rb+, despite the similarities in overall charging. Adsorbed sodium ions are almost exclusively found in bidentate surface complexes, while adsorbed rubidium ions form comparable amounts of bidentate and tetradentate complexes. Also, the distribution of adsorbed Na+ between the different complexes shows a considerable dependence on surface charge density (pH), while the distribution of adsorbed Rb+ is almost independent of pH. A Surface Complexation Model (SCM) capable of accurately describing both the measured surface charge and the MD predicted speciation of adsorbed Na+/Rb+ was formulated. According to the SCM, the deprotonated terminal group (SnOH-0.40) and the protonated bridging group (Sn2OH+0.36) dominate the surface speciation over the entire pH-range (2.7 10), illustrating the ability of positively and negatively charged surface groups to coexist. Complexation of the medium cations increases significantly with increasing negative surface charge and at pH 10 roughly 40 percent of the terminal sites are predicted to form cation complexes, while anion complexation is minor throughout the studied pH-range.

  5. Ethanol Steam Reforming on Co/CeO2: The Effect of ZnO Promoter

    SciTech Connect (OSTI)

    Davidson, Stephen; Sun, Junming; Wang, Yong

    2013-12-02

    A series of ZnO promoted Co/CeO2 catalysts were synthesized and characterized using XRD, TEM, H2-TPR, CO chemisorption, O2-TPO, IR-Py, and CO2-TPD. The effects of ZnO on the catalytic performances of Co/CeO2 were studied in ethanol steam reforming. It was found that the addition of ZnO facilitated the oxidation of Co0 via enhanced oxygen mobility of the CeO2 support which decreased the activity of Co/CeO2 in C–C bond cleavage of ethanol. 3 wt% ZnO promoted Co/CeO2 exhibited minimum CO and CH4 selectivity and maximum CO2 selectivity. This resulted from the combined effects of the following factors with increasing ZnO loading: (1) enhanced oxygen mobility of CeO2 facilitated the oxidation of CHx and CO to form CO2; (2) increased ZnO coverage on CeO2 surface reduced the interaction between CHx/CO and Co/CeO2; and (3) suppressed CO adsorption on Co0 reduced CO oxidation rate to form CO2. In addition, the addition of ZnO also modified the surface acidity and basicity of CeO2, which consequently affected the C2–C4 product distributions.

  6. I.. , .., I.., .. i i H2, H2O ii i i SiO2

    E-Print Network [OSTI]

    of the adsorbtion of H2, H2O and uranyl ions on the SiO2 surface I.V. Stasyuk,T.S.Mysakovych, I.R.Dulepa, V.O.Krasnov Abstract. Using the quantum chemical calculations the adsorption of H2, H2O and uranyl ions on the SiO2 into atoms take place at the adsorption. The adsorption of the uranyl ions on the SiO2 surface was the object

  7. Photocatalytic Inhibition of Algae Growth Using TiO2, WO3, and

    E-Print Network [OSTI]

    Ouellette, Anthony J. A.

    Photocatalytic Inhibition of Algae Growth Using TiO2, WO3, and Cocatalyst Modifications C L O V I Road, Cocoa, Florida 32922-5703 TiO2 and WO3, with and without noble metal cocatalysts, were employed structures. Introduction Wide band gap metal oxides such as TiO2 and WO3 (Eg ) 3.1 and 2.7 eV, respectively

  8. KINETICS, CATALYSIS, AND REACTION ENGINEERING Staged O2 Introduction and Selective H2 Combustion during

    E-Print Network [OSTI]

    Iglesia, Enrique

    KINETICS, CATALYSIS, AND REACTION ENGINEERING Staged O2 Introduction and Selective H2 Combustion2 increased the selectivity of propane conversion to aromatics o

  9. Synthesis of Highly Ordered TiO2 Nanotubes Using Ionic Liquids for Photovoltaics Applications

    SciTech Connect (OSTI)

    2009-04-01

    This factsheet describes a study that deals with a new, ‘green’ approach of synthesizing highly ordered TiO2 nanotubes using ionic liquids for photovoltaics (PV) applications.

  10. Evolution of Hollow TiO2 Nanostructures via the Kirkendall Effect Driven by Cation Exchange with Enhanced Photoelectrochemical

    E-Print Network [OSTI]

    Wang, Xudong

    . The evolution of TiO2 nanotubes from ZnO NW scaffolds was seamlessly integrated with TiO2 NR branch growthEvolution of Hollow TiO2 Nanostructures via the Kirkendall Effect Driven by Cation Exchange. In this paper, we report a discovery of hollow TiO2 nanostructure evolution in a vapor-solid deposition system

  11. Introduction The vertebrate O2 transport and delivery system can be

    E-Print Network [OSTI]

    Saltzman, Wendy

    of the increase O2 gradient.] We compared maximum aerobic capacity during forced exercise (VO22max) in hypoxia (PO in a metabolic chamber that allowed altered PO22. Individual variation in VO22max was highly repeatable within metabolism if central organs provide more O2. Although the existence of central limitations in S lines cannot

  12. Stochastic bi-resonance without external signal in the CO O2 catalytic oxidation reaction system

    E-Print Network [OSTI]

    Yang, Lingfa

    Stochastic bi-resonance without external signal in the CO O2 catalytic oxidation reaction system reaction systems13 including the catalytic oxidation of carbon monoxide (CO O2) and the catalytic reduction; accepted 19 April 1999 The noisy dynamic behavior of a surface catalytic reaction model to describe

  13. Enhanced Electrochemical Lithium Storage Activity of LiCrO2 by Size Effect

    SciTech Connect (OSTI)

    Feng, G.; Li, L; Liu, J; Liu, N; Li, H; Yang, X; Huang, X; Chen, L; Nam, K; Yoon, W

    2009-01-01

    Cr8O21 was chemically lithiated using a lithium-biphenyl-dimethoxyethane solution. Lithiated Cr8O21 shows a structure in which as-formed LiCrO2 units are sandwiched between Cr2O3 superlattice layers. Chemically lithiated Cr8O21 shows a delithiation capacity of 200 mAh g-1. It means that LiCrO2 units in lithiated Cr8O21 are electrochemically active. This finding is opposite to previous reports that LiCrO2 materials have very poor Li-storage capacities. Our new result implies that LiCrO2 with extremely small domain size could show enhanced reactivity. This proposal is proved unambiguously by the fact that LiCrO2 powder materials with smaller grain size (<20 nm) show much higher capacities than LiCrO2 materials with larger grain size (>50 nm). In addition, it is found that the cation mixing is more significantly in LiCrO2 materials with smaller grain size, which seems a key factor for the storage and transport of lithium in layered Cr-based materials. The cation mixing may also explain the result that the lattice parameters of LiCrO2 do not change significantly upon lithium extraction and insertion, investigated by in situ and ex situ XRD techniques.

  14. MODELING AND CONTROL OF A O2/CO2 GAS TURBINE CYCLE FOR CO2 CAPTURE

    E-Print Network [OSTI]

    Foss, Bjarne A.

    MODELING AND CONTROL OF A O2/CO2 GAS TURBINE CYCLE FOR CO2 CAPTURE Lars Imsland Dagfinn Snarheim and control of a semi-closed O2/CO2 gas turbine cycle for CO2 capture. In the first part the process predictive control, Gas turbines, CO2 capture 1. INTRODUCTION Gas turbines are widely used for power

  15. Hard templating synthesis of mesoporous and nanowire SnO2 lithium battery anode materials

    E-Print Network [OSTI]

    Cho, Jaephil

    Hard templating synthesis of mesoporous and nanowire SnO2 lithium battery anode materials Hyesun materials for lithium batteries were prepared using KIT-6 and SBA-15 SiO2 templates as an anode material for lithium batteries due to its high capacity (>600 mAh gÀ1 ) compared with graphite

  16. Electrochemical Monitoring of TiO2 Atomic Layer Deposition by Chronoamperometry and Scanning Electrochemical Microscopy

    E-Print Network [OSTI]

    Yu, Edward T.

    Electrochemical Monitoring of TiO2 Atomic Layer Deposition by Chronoamperometry and Scanning) was used to characterize the atomic layer deposition (ALD) of TiO2 on indium-doped tin oxide (ITO). KEYWORDS: atomic layer deposition (ALD), scanning electrochemical microscopy (SECM), nanoporous films

  17. Application of SiO2 aerogel film with low dielectric constant to intermetal dielectrics

    E-Print Network [OSTI]

    Jo, Moon-Ho

    Application of SiO2 aerogel film with low dielectric constant to intermetal dielectrics Moon-Ho Jo aerogel film was characterized from its structural and chemical viewpoints. High porosity of material infrared spectroscopy (FT-IR) for their chemical states. The improved electrical properties of SiO2 aerogel

  18. THREE-DIMENSIONAL ATOMIC STRUCTURE OF NiO ZrO2(CUBIC) INTERFACES

    E-Print Network [OSTI]

    Pennycook, Steve

    THREE-DIMENSIONAL ATOMIC STRUCTURE OF NiO± ZrO2(CUBIC) INTERFACES E. C. DICKEY{1 , V. P. DRAVID1-dimensional atomic structure of low-energy NiO±ZrO2(cubic) interfaces is determined through a combination of electron the structural and chemical aspects of the interface and associ- ated interfacial relaxation mechaubic) interface

  19. Dimerization Induced Deprotonation of Water on RuO2(110)

    SciTech Connect (OSTI)

    Mu, Rentao; Cantu Cantu, David; Lin, Xiao; Glezakou, Vassiliki Alexandra; Wang, Zhitao; Lyubinetsky, Igor; Rousseau, Roger J.; Dohnalek, Zdenek

    2014-10-02

    RuO2 has proven to be indispensable as a co-catalyst in numerous systems designed for photocatalytic water splitting. In this study we have carried out a detailed mechanistic study of water behavior on the most stable RuO2 face, RuO2(110), by employing variable temperature scanning tunneling microscopy and density functional theory calculations. We show that water monomers adsorb molecularly on Ru sites, become mobile above 238 K, diffuse along the Ru rows and form water dimers. The onset for dimer diffusion is observed at ~277 K indicating significantly higher diffusion barrier than that for monomers. More importantly, we find that water dimers deprotonate readily to form Ru-bound H3O2 and bridging OH species. The observed behavior is compared and contrasted with that observed for water on isostructural rutile TiO2(110).

  20. OpenEI Community - iot

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History ViewMayo, Maryland:NPI VenturesNewSt.Information OlindaOnslow County,OpTICOpenBarter Jump

  1. iot | OpenEI Community

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EAand Dalton Jump to:Wylie, Texas: EnergyYBRZAPgftID

  2. Formation of Interfacial Layer and Long-Term Cylability of Li-O-2 Batteries

    SciTech Connect (OSTI)

    Nasybulin, Eduard N.; Xu, Wu; Mehdi, Beata L.; Thomsen, Edwin C.; Engelhard, Mark H.; Masse, Robert C.; Bhattacharya, Priyanka; Gu, Meng; Bennett, Wendy D.; Nie, Zimin; Wang, Chong M.; Browning, Nigel D.; Zhang, Jiguang

    2014-08-27

    Extended cycling of the Li-O2 battery under full discharge/charge conditions is achievable upon selection of appropriate electrode materials and cycling protocol. However, the decomposition of the side products also contribute to the observed good cycling behavior of high capacity Li-O2 batteries. Quantitative analyses of the discharge and charge products reveals a quick switch from the predominant formation of Li2O2 to the predominant formation of side products during the first a few cycles of the Li-O2 batteries. After the switch, cycling stabilizes with a repeatable formation of Li2O2/side products at ~1:2 ratio. CNTs/Ru composite electrodes exhibits lower charge voltage and deliver 50 full discharge-charge cycles without sharp capacity drop. Ru coated glass carbon electrode can lead to more than 500 cycles without change in its cycling profiles. The better understanding on Li-O2 reaction processes developed in this work may lead to the further improvement on the long term cycling behavior of high capacity Li-O2 batteries.

  3. Doping of TiO 2 Polymorphs for Altered Optical and Photocatalytic Properties

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Nie, Xiliang; Zhuo, Shuping; Maeng, Gloria; Sohlberg, Karl

    2009-01-01

    This paper reviews recent investigations of the influence of dopants on the optical properties of TiO 2 polymorphs. The common undoped polymorphs of TiO 2 are discussed and compared. The results of recent doping efforts are tabulated, and discussed in the context of doping by elements of the same chemical group. Dopant effects on the band gap and photocatalytic activity are interpreted with reference to a simple qualitative picture of the TiO 2 electronic structure,more »which is supported with first-principles calculations. « less

  4. Balance the reaction MnO4 (aq) MnO2(s) + SO4

    E-Print Network [OSTI]

    Peterson, Kirk A.

    Balance the reaction MnO4 Ð (aq) + SO3 2Ð (aq) MnO2(s) + SO4 2Ð (aq) in basic solution Oxidation 2Ð SO4 2Ð (b) 2) These are already balanced in Mn and S 3) Balance O in (a) by adding H2OÕs to the right-hand-side MnO4 Ð MnO2 + 2H2O 4) Balance H by adding H + to the left-hand-side MnO4 Ð + 4H + MnO2

  5. Doping ofTiO2Polymorphs for Altered Optical and Photocatalytic Properties

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Nie, Xiliang; Zhuo, Shuping; Maeng, Gloria; Sohlberg, Karl

    2009-01-01

    This paper reviews recent investigations of the influence of dopants on the optical properties ofTiO2polymorphs. The common undoped polymorphs ofTiO2are discussed and compared. The results of recent doping efforts are tabulated, and discussed in the context of doping by elements of the same chemical group. Dopant effects on the band gap and photocatalytic activity are interpreted with reference to a simple qualitative picture of theTiO2electronic structure, which is supported with first-principles calculations.

  6. DNA Cleavage by Photogenerated Rh2(O2CCH3)4(H2O)2 Patty K.-L. Fu, Patricia M. Bradley, and Claudia Turro*

    E-Print Network [OSTI]

    Turro, Claudia

    the subject of intense investigation since, upon light activation, they can act as reporters of DNA structure and coordination of the dirhodium core to single-stranded oligonucleotides has been observed, the mode of binding-methylpyridinium tetrafluoroborate (py+),17 results in the formation of the one-electron-oxidized complex, Rh2(O2

  7. Microchannel Reactor System Design & Demonstration For On-Site H2O2 Production by Controlled H2/O2 Reaction

    SciTech Connect (OSTI)

    Adeniyi Lawal

    2008-12-09

    We successfully demonstrated an innovative hydrogen peroxide (H2O2) production concept which involved the development of flame- and explosion-resistant microchannel reactor system for energy efficient, cost-saving, on-site H2O2 production. We designed, fabricated, evaluated, and optimized a laboratory-scale microchannel reactor system for controlled direct combination of H2 and O2 in all proportions including explosive regime, at a low pressure and a low temperature to produce about 1.5 wt% H2O2 as proposed. In the second phase of the program, as a prelude to full-scale commercialization, we demonstrated our H2O2 production approach by ‘numbering up’ the channels in a multi-channel microreactor-based pilot plant to produce 1 kg/h of H2O2 at 1.5 wt% as demanded by end-users of the developed technology. To our knowledge, we are the first group to accomplish this significant milestone. We identified the reaction pathways that comprise the process, and implemented rigorous mechanistic kinetic studies to obtain the kinetics of the three main dominant reactions. We are not aware of any such comprehensive kinetic studies for the direct combination process, either in a microreactor or any other reactor system. We showed that the mass transfer parameter in our microreactor system is several orders of magnitude higher than what obtains in the macroreactor, attesting to the superior performance of microreactor. A one-dimensional reactor model incorporating the kinetics information enabled us to clarify certain important aspects of the chemistry of the direct combination process as detailed in section 5 of this report. Also, through mathematical modeling and simulation using sophisticated and robust commercial software packages, we were able to elucidate the hydrodynamics of the complex multiphase flows that take place in the microchannel. In conjunction with the kinetics information, we were able to validate the experimental data. If fully implemented across the whole industry as a result of our technology demonstration, our production concept is expected to save >5 trillion Btu/year of steam usage and >3 trillion Btu/year in electric power consumption. Our analysis also indicates >50 % reduction in waste disposal cost and ~10% reduction in feedstock energy. These savings translate to ~30% reduction in overall production and transportation costs for the $1B annual H2O2 market.

  8. Synthesis of TiO2 photocatalyst and study on their improvement technology of photocatalytic activity

    E-Print Network [OSTI]

    Boo, Jin-Hyo

    was evaluated by the measurements of the UV/vis. irradiation, infrared spectroscopy, XPS, and contact angleO2) plays an important role in a variety of technological applications ranging from sensors

  9. Nanocrystallization of LiCoO2 Cathodes for Thin Film Batteries Utilizing Pulse Thermal Processing

    SciTech Connect (OSTI)

    2009-04-01

    This factsheet describes a study whose focus is on the nanocrystallization of the LiCoO2 cathode thin films on polyimide substrates and evaluate the microstructural evolution and resistance as a function of PTP processing conditions.

  10. Invoking any Intel compiler with -g defaults to -O2 optimization...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Invoking any Intel compiler with a Cray wrapper with -g defaults to -O2 optimization contrary to the Intel compiler man pages Invoking any Intel compiler with a Cray wrapper with...

  11. DNA nanoconjugates Labeling TiO2 Nanoparticles with Dyes for Optical

    E-Print Network [OSTI]

    Brown, Eric

    signal as mapped by XFM. This strongly implies the intracellular integrity of the TiO2­DNA nanoconjugates Indian Institute of Technology Bombay Powai Mumbai 400076 (India) Prof. V. Dravid Department of Material

  12. Macroporous TiO2 Photoanodes for High Efficiency PSI-Based Biohybrid Photovoltaics

    E-Print Network [OSTI]

    Macroporous TiO2 Photoanodes for High Efficiency PSI-Based Biohybrid Photovoltaics and efficiency of PSI-based biohybrid photovoltaics due to the high integraVon of PSI

  13. Molecular Hydrogen Formation from Proximal Glycol Pairs on TiO2(110)

    SciTech Connect (OSTI)

    Chen, Long; Li, Zhenjun; Smith, R. Scott; Kay, Bruce D.; Dohnalek, Zdenek

    2014-04-16

    Understanding hydrogen formation on TiO2 surfaces is of great importance as it could provide fundamental insight into water splitting for hydrogen production using solar energy. In this work, hydrogen formation from glycols having different numbers of methyl end-groups have been studied using temperature pro-grammed desorption on reduced, hydroxylated, and oxidized TiO2(110) surfaces. The results from OD-labeled glycols demon-strate that gas-phase molecular hydrogen originates exclusively from glycol hydroxyl groups. The yield is controlled by a combi-nation of glycol coverage, steric hindrance, TiO2(110) order and the amount of subsurface charge. Combined, these results show that proximal pairs of hydroxyl aligned glycol molecules and subsurface charge are required to maximize the yield of this redox reaction. These findings highlight the importance of geometric and electronic effects in hydrogen formation from adsorbates on TiO2(110).

  14. Effect of Spin-Orbit Coupling on the Actinide Dioxides AnO2 ...

    Office of Scientific and Technical Information (OSTI)

    Coupling on the Actinide Dioxides AnO2 (AnTh, Pa, U, Np, Pu, and Am): A Screened Hybrid Density Functional Study Citation Details In-Document Search Title: Effect of...

  15. Scanning tunneling microscopic studies of SiO2 thin film supported metal nano-clusters 

    E-Print Network [OSTI]

    Min, Byoung Koun

    2005-11-01

    This dissertation is focused on understanding heterogeneous metal catalysts supported on oxides using a model catalyst system of SiO2 thin film supported metal nano-clusters. The primary technique applied to this study is scanning tunneling...

  16. Porous TiO2 microspheres with tunable properties for photocatalytic air purification Alberto Naldoni a,

    E-Print Network [OSTI]

    Suslick, Kenneth S.

    2012 Keywords: TiO2 Nanostructured microsphere Silica Photocatalysis NOx a b s t r a c t The synthesis, photonic materials, batteries and membrane fuel cells, and photocatalysis [7­15]. Titanium dioxide

  17. NOx-Mediated Homogeneous Pathways for the Synthesis of Formaldehyde from CH4-O2 Mixtures

    E-Print Network [OSTI]

    Iglesia, Enrique

    NOx-Mediated Homogeneous Pathways for the Synthesis of Formaldehyde from CH4-O2 Mixtures Jeffrey M-NOx reactions is used to estimate maximum attainable formaldehyde (and methanol) yields

  18. O2-06-05 AVOXEL-BASED MORPHOMETRY STUDY OF VOLUMETRIC MRI IN FAMILIAL ALZHEIMER'S

    E-Print Network [OSTI]

    Thompson, Paul

    O2-06-05 AVOXEL-BASED MORPHOMETRY STUDY OF VOLUMETRIC MRI IN FAMILIAL ALZHEIMER'S DISEASE David the different groups. Tissue segmentation and spatial normalization of volumetric T1-weighted images were

  19. Formation of various TiO2 nanostructures from electrochemically anodized titanium

    E-Print Network [OSTI]

    Lin, Zhiqun

    widely exploited for use in the areas of gas sensors,2­4 hydrogen generation,5,6 photo- catalysts,7,8 cell separation,9 dye sensitized solar cells (DSSC),10­19 and quantum dot20­26 sensitized solar cells TiO2 nanotube is perpendicular to the membrane surface.16,29­31 Since the as-prepared anodic TiO2

  20. Electrochemical Properties of Disordered-Carbon-Coated SnO2 Nanoparticles for Li Rechargeable Batteries

    E-Print Network [OSTI]

    Park, Byungwoo

    Batteries Taeho Moon, Chunjoong Kim, Sun-Tae Hwang, and Byungwoo Park*,z School of Materials Science batteries.1-5 It is rationalized that the reactions of SnO2 with lithium are SnO2 + 4Li Sn + 2Li2O and Sn is to distribute nanoparticles uniformly on a large matrix such as graphite, mesoporous carbon, etc.12,13 However

  1. ALMA observations of TiO$_2$ around VY Canis Majoris

    E-Print Network [OSTI]

    De Beck, E; Muller, S; Black, J H; O'Gorman, E; Richards, A M S; Baudry, A; Maercker, M; Decin, L; Humphreys, E M

    2015-01-01

    Titanium dioxide, TiO$_2$, is a refractory species that could play a crucial role in the dust-condensation sequence around oxygen-rich evolved stars. To date, gas phase TiO$_2$ has been detected only in the complex environment of the red supergiant VY CMa. We aim to constrain the distribution and excitation of TiO$_2$ around VY CMa in order to clarify its role in dust formation. We analyse spectra and channel maps for TiO$_2$ extracted from ALMA science verification data. We detect 15 transitions of TiO$_2$, and spatially resolve the emission for the first time. The maps demonstrate a highly clumpy, anisotropic outflow in which the TiO$_2$ emission likely traces gas exposed to the stellar radiation field. A roughly east-west oriented, accelerating bipolar-like structure is found, of which the blue component runs into and breaks up around a solid continuum component. A distinct tail to the south-west is seen for some transitions, consistent with features seen in the optical and near-infrared. We find that a si...

  2. Results from ORNL characterization of ZrO2-500-AK2 - surrogate TRISO material

    SciTech Connect (OSTI)

    Kercher, Andrew K [ORNL; Hunn, John D [ORNL

    2005-06-01

    This document is a compilation of the characterization data for the TRISO-coated surrogate particles designated ZrO2-500-AK2 that was produced at Oak Ridge National Laboratory (ORNL) as part of the Advanced Gas Reactor Fuel Development and Qualification (AGR) program. The ZrO2-500-AK2 material contains nominally 500 {micro}m kernels of yttria-stabilized zirconia (YSZ) coated with all TRISO layers (buffer, inner pyrocarbon, silicon carbide, and outer pyrocarbon). The ZrO2-500-AK2 material was created for: (1) irradiation testing in the High Flux Isotope Reactor (HFIR) and (2) limited dissemination to laboratories as deemed appropriate to the AGR program. This material was created midway into a TRISO fuel development program to accommodate a sudden opportunity to perform irradiation testing on surrogate material. While the layer deposition processes were chosen based on the best technical understanding at the time, technical progress at ORNL has led to an evolution in the perceived optimal deposition conditions since the creation of ZrO2-500-AK2. Thus, ZrO2-500-AK2 contains a reasonable TRISO microstructure, but does differ significantly from currently produced TRISO surrogates and fuel at ORNL. In this document, characterization data of the ZrO2-500-AK2 surrogate includes: size, shape, coating thickness, and density.

  3. Composite WO3/TiO2 nanostructures for high electrochromic activity.

    SciTech Connect (OSTI)

    Reyes, Karla Rosa; Stephens, Zachary Dan.; Robinson, David B.

    2013-05-01

    A composite material consisting of TiO2 nanotubes (NTs) with WO3 electrodeposited homogeneously on its surface has been fabricated, detached from its substrate, and attached to a fluorine-doped tin oxide film on glass for application to electrochromic (EC) reactions. A paste of TiO2 made from commercially available TiO2 nanoparticles creates an interface for the TiO2 NT film to attach to the FTO glass, which is conductive and does not cause solution-phase ions in an electrolyte to bind irreversibly with the material. The effect of NT length on the current density and the EC contrast of the material were studied. The EC redox reaction seen in this material is diffusion- limited, having relatively fast reaction rates at the electrode surface. The composite WO3/TiO2 nanostructures showed higher ion storage capacity, better stability, enhanced EC contrast and longer memory time compared with the pure WO3 and TiO2.

  4. Location Of Hole And Electron Traps On Nanocrystalline Anatase TiO2

    SciTech Connect (OSTI)

    Mercado, Candy C.; Knorr, Fritz J.; McHale, Jeanne L.; Usmani, Shirin M.; Ichimura, Andrew S.; Saraf, Laxmikant V.

    2012-05-17

    The defect photoluminescence from TiO2 nanoparticles in the anatase phase is reported for nanosheets which expose predominantly (001) surfaces, and compared to that from conventional anatase nanoparticles which expose mostly (101) surfaces. Also reported is the weak defect photoluminescence of TiO2 nanotubes, which we find using electron back-scattered diffraction to consist of walls which expose (110) and (100) facets. The nanotubes exhibit photoluminescence that is blue-shifted and much weaker than that from conventional TiO2 nanoparticles. Despite the preponderance of (001) surfaces in the nanosheet samples, they exhibit photoluminescence similar to that of conventional nanoparticles. We assign the broad visible photoluminescence of anatase nanoparticles to two overlapping distributions: hole trap emission associated with oxygen vacancies on (101) exposed surfaces, which peaks in the green, and a broader emission extending into the red which results from electron traps on under-coordinated titanium atoms, which are prevalent on (001) facets. The results of this study suggest how morphology of TiO2 nanoparticles could be optimized to control the distribution and activity of surface traps. Our results also shed light on the mechanism by which the TiCl4 surface treatment heals traps on anatase and mixed-phase TiO2 films, and reveals distinct differences in the trap-state distributions of TiO2 nanoparticles and nanotubes. The molecular basis for electron and hole traps and their spatial separation on different facets is discussed.

  5. Titanium oxide (TiO2), an abundant material with photocatalytic activity and chemical stability is an important candidate for photocatalytic applications. The photocatalytic activity of the TiO2

    E-Print Network [OSTI]

    phase. In the current project, phase and morphology changes in TiO2 nanotubes were studied using ex studies were also performed to understand the phase and morphology of the nanotubes. As prepared TiO2 nanotubes transform to anatase at 450 oC and transformed to rutile when heated to 800 oC. TiO2 nanotubes

  6. Development of Compact Gaseous Sensors with Internal Reference for Monitoring O2 and NOx in Combustion Environments

    Broader source: Energy.gov [DOE]

    Compact sensors have been developed to allow for real-time monitoring of O2 and NOx during combustion.

  7. Effects of electrolyte salts on the performance of Li-O2 batteries

    SciTech Connect (OSTI)

    Nasybulin, Eduard N.; Xu, Wu; Engelhard, Mark H.; Nie, Zimin; Burton, Sarah D.; Cosimbescu, Lelia; Gross, Mark E.; Zhang, Jiguang

    2013-02-05

    It is well known that the stability of nonaqueous electrolyte is critical for the rechargeable Li-O2 batteries. Although stability of many solvents used in the electrolytes has been investigated, considerably less attention has been paid to the stability of electrolyte salt which is the second major component. Herein, we report the systematic investigation of the stability of seven common lithium salts in tetraglyme used as electrolytes for Li-O2 batteries. The discharge products of Li-O2 reaction were analyzed by X-ray diffraction, X-ray photoelectron spectroscopy and nuclear magnetic resonance spectroscopy. The performance of Li-O2 batteries was strongly affected by the salt used in the electrolyte. Lithium tetrafluoroborate (LiBF4) and lithium bis(oxalato)borate (LiBOB) decompose and form LiF and lithium borates, respectively during the discharge of Li-O2 batteries. Several other salts, including lithium bis(trifluoromethane)sulfonamide (LiTFSI), lithium trifluoromethanesulfonate (LiTf), lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4) , and lithium bromide (LiBr) led to the discharge products which mainly consisted of Li2O2 and only minor signs of decomposition of LiTFSI, LiTf, LPF6 and LiClO4 were detected. LiBr showed the best stability during the discharge process. As for the cycling performance, LiTf and LiTFSI were the best among the studied salts. In addition to the instability of lithium salts, decomposition of tetraglyme solvent was a more significant factor contributing to the limited cycling stability. Thus a more stable nonaqueous electrolyte including organic solvent and lithium salt still need to be further developed to reach a fully reversible Li-O2 battery.

  8. Photodissociation of Ozone from 321 to 329 nm: The Relative Yields P2) with O2(X 3

    E-Print Network [OSTI]

    Houston, Paul L.

    Photodissociation of Ozone from 321 to 329 nm: The Relative Yields of O(3 P2) with O2(X 3 g - ), O2 Supporting Information ABSTRACT: Product imaging of O(3 P2) following dissociation of ozone has been used to determine the relative yields of the product channels O(3 P2) + O2(X 3 g - ) of ozone. All three channels

  9. DOI: 10.1002/asia.201200349 Dye-Sensitized TiO2 Nanotube Solar Cells: Rational Structural and Surface

    E-Print Network [OSTI]

    Lin, Zhiqun

    DOI: 10.1002/asia.201200349 Dye-Sensitized TiO2 Nanotube Solar Cells: Rational Structural and Surface Engineering on TiO2 Nanotubes Jun Wang[a] and Zhiqun Lin*[b] 2754 2012 Wiley-VCH Verlag GmbH & Co-defined structural parameters and enhanced electronic properties, highly ordered TiO2 nanotube arrays have been

  10. Redox probing study of the potential dependence of charge transport through Li2O2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Knudsen, Kristian B.; Luntz, Alan C.; Jensen, Søren H.; Vegge, Tejs; Hjelm, Johan

    2015-11-20

    In the field of energy storage devices the pursuit for cheap, high energy density, reliable secondary batteries is at the top of the agenda. The Li–O2 battery is one of the possible technologies that, in theory, should be able to close the gap, which exists between the present state-of-the-art Li-ion technologies and the demand placed on batteries by technologies such as electrical vehicles. Here we present a redox probing study of the charge transfer across the main deposition product lithium peroxide, Li2O2, in the Li–O2 battery using outer-sphere redox shuttles. The change in heterogeneous electron transfer exchange rate as amore »function of the potential and the Li2O2 layer thickness (~depth-of-discharge) was determined using electrochemical impedance spectroscopy. In addition, the attenuation of the electron transfer exchange rate with film thickness is dependent on the probing potential, providing evidence that hole transport is the dominant process for charge transfer through Li2O2 and showing that the origin of the sudden death observed upon discharge is due to charge transport limitations.« less

  11. WO3/TiO2 nanotube photoanodes for solar water splitting with simultaneous wastewater treatment.

    SciTech Connect (OSTI)

    Reyes, Karla Rosa; Robinson, David B.

    2013-05-01

    Nanostructured WO3/TiO2 nanotubes with properties that enhance solar photoconversion reactions were developed, characterized and tested. The TiO2 nanotubes were prepared by anodization of Ti foil, and WO3 was electrodeposited on top of the nanotubes. SEM images show that these materials have the same ordered structure as TiO2 nanotubes, with an external nanostructured WO3 layer. Diffuse reflectance spectra showed an increase in the visible absorption relative to bare TiO2 nanotubes, and in the UV absorption relative to bare WO3 films. Incident simulated solar photon-to-current efficiency increased from 30% (for bare WO3) to 50% (for WO3/TiO2 composites). With the addition of diverse organic pollutants, the photocurrent densities exhibited more than a 5-fold increase. Chemical oxygen demand measurements showed the simultaneous photodegradation of organic pollutants. The results of this work indicate that the unique structure and composition of these composite materials enhance the charge carrier transport and optical properties compared with the parent materials.

  12. Synthesis and Characterization of PhotocatalyticTiO2-ZnFe2O4Nanoparticles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Srinivasan, Sesha S.; Wade, Jeremy; Stefanakos, Elias K.

    2006-01-01

    A new coprecipitation/hydrolysis synthesis route is used to create aTiO2-ZnFe2O4nanocomposite that is directed towards extending the photoresponse ofTiO2from UV to visible wavelengths (>400?nm). The effect ofTiO2's accelerated anatase-rutile phase transformation due to the presence of the coupledZnFe2O4narrow-bandgap semiconductor is evaluated. The transformation's dependence on pH, calcinations temperature, particle size, andZnFe2O4concentration has been analyzed using XRD, SEM, and UV-visible spectrometry. The requirements for retaining the highly photoactive anatase phase present in aZnFe2O4nanocomposite are outlined. The visible-light-activated photocatalytic activity of theTiO2-ZnFe2O4nanocomposites has been compared to an AldrichTiO2reference catalyst, using a solar-simulated photoreactor formore »the degradation of phenol.« less

  13. Visible-light active TiO2 for microwave assisted photocatalytic reactions using mercury electrodeless discharge lamps

    E-Print Network [OSTI]

    Cirkva, Vladimir

    of transition metal ions in wt.% was determined by electron microprobe Ag/TiO2: 143 (Eg) 196 (Eg) 395 (B1g) 513 (A1g) 519 (B1g) 638 (Eg) -50 0 50 100 150 200 250 300 350 400 Int 5001000 Raman shift (cm-1) Raman spectroscopy anatase TiO2: A1g+2B1g+3Eg (Eg) (A1g) (B1g) (B1g) (Eg) (Eg) A B C D A-TiO2 B-V/TiO2 C-Zr/TiO2 D

  14. Dendrimer-Encapsulated Ruthenium Nanoparticles as Catalysts for Lithium-O2 Batteries

    SciTech Connect (OSTI)

    Bhattacharya, Priyanka; Nasybulin, Eduard N.; Engelhard, Mark H.; Kovarik, Libor; Bowden, Mark E.; Li, Shari; Gaspar, Daniel J.; Xu, Wu; Zhang, Jiguang

    2014-12-01

    Dendrimer-encapsulated ruthenium nanoparticles (DEN-Ru) have been used as catalysts in lithium-O2 batteries for the first time. Results obtained from UV-vis spectroscopy, electron microscopy and X-ray photoelectron spectroscopy show that the nanoparticles synthesized by the dendrimer template method are ruthenium oxide instead of metallic ruthenium reported earlier by other groups. The DEN-Ru significantly improve the cycling stability of lithium (Li)-O2 batteries with carbon black electrodes and decrease the charging potential even at low catalyst loading. The monodispersity, porosity and large number of surface functionalities of the dendrimer template prevent the aggregation of the ruthenium nanoparticles making their entire surface area available for catalysis. The potential of using DEN-Ru as stand-alone cathode materials for Li-O2 batteries is also explored.

  15. Visible Light Photocatalysis via CdS/TiO2Nanocomposite Materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Srinivasan, Sesha S.; Wade, Jeremy; Stefanakos, Elias K.

    2006-01-01

    Nanostructured colloidal semiconductors with heterogeneous photocatalytic behavior have drawn considerable attention over the past few years. This is due to their large surface area, high redox potential of the photogenerated charge carriers, and selective reduction/oxidation of different classes of organic compounds. In the present paper, we have carried out a systematic synthesis of nanostructured CdS-TiO2via reverse micelle process. The structural and microstructural characterizations of the as-prepared CdS-TiO2nanocomposites are determined using XRD and SEM-EDS techniques. The visible light assisted photocatalytic performance is monitored by means of degradation of phenol in water suspension.

  16. Transmission Electron Microscopy Investigation of Krypton Bubbles in Polycrystalline CeO2

    SciTech Connect (OSTI)

    Lingfeng He; Clarissa Yablinsky; Mahima Gupta; Jian Gan; Marquis A. Kirk; Todd R. Allen

    2013-05-01

    To gain an understanding of gas bubble transport in oxide nuclear fuel, this paper uses polycrystalline CeO2, composed of both nanograins and micrograins, as a surrogate material for UO2. The CeO2 was implanted with 150-keV Kr ions up to a dose of 1 x 1016 ions/cm2 at 600 degrees C. Transmission electron microscopy characterizations of small Kr bubbles in nanograin and micrograin regions were compared. The grain boundary acted as an efficient defect sink, as evidenced by smaller bubbles and a lower bubble density in the nanograin region as compared to the micrograin region.

  17. Adsorption of water on O(2x2)/Ru(0001): thermal stability and inhibition of dissociation by H2O-O bonding

    E-Print Network [OSTI]

    Mugarza, Aitor

    2009-01-01

    On the O(2x2) areas intact water monomers are still visible.Adsorption of water on O(2x2)/Ru(0001): thermal stabilityJapan. Adsorption of water on O(2x2)/Ru(0001) Corresponding

  18. Photoelectrochemical Water Splitting of Nitrogen and Hydrogen Treated P25 TiO2 Films

    E-Print Network [OSTI]

    Zavodivker, Liat Shari

    2014-01-01

    Quantum Dot Solar Cells. Harvesting Light Energy with CdSeSolar Cells by Design: Photoelectrochemistry of TiO 2 Nanorod Arrays Decorated with CdSe.Solar Cells. Tuning Photoresponse through Size and Shape Control of CdSe

  19. The pore wall structure of porous semi-crystalline anatase TiO2.

    SciTech Connect (OSTI)

    Kim, Dr Man-Ho [National Institute of Standards and Technol/University of Maryland, College Park; Doh, Dr. Jeong-Mann [Harbin Institute of Technology & Korea Institute of Science and Technology; Han, Seong Chul [Harbin Institute of Technology & Korea Institute of Science and Technology; Chae, Keun Hwa [Harbin Institute of Technology & Korea Institute of Science and Technology; Yu, Byung-Yong [Harbin Institute of Technology & Korea Institute of Science and Technology; Hong, Kyung Tea [Harbin Institute of Technology & Korea Institute of Science and Technology; Jackson, Andrew [NIST Center for Neutron Research (NCRN), Gaithersburg, MD; Anovitz, Lawrence {Larry} M [ORNL

    2011-01-01

    The structure of porous TiO2 prepared by electrochemical anodization in a fluoride-containing ethylene glycol electrolyte solution was quantitatively studied using small-angle neutron scattering (SANS) and ultra-small-angle neutron scattering (USANS). The cylindrical pores along the coaxial direction were somewhat irregular in shape, were widely distributed in diameter, and seemed to have a broadly pseudo-hexagonal arrangement. The scattering from the pore wall showed a negative deviation from Porod scattering, indicating that the interface between TiO2 and the pore was not sharp. A density gradient of around 40 60 A at the pore wall (i.e. the interface between the pore and the TiO2 matrix) was estimated using both constant and semi-sigmoidal interface models. This gradient may be due to the presence of fluorine and carbon partially absorbed by the pore wall from the fluoride-containing electrolyte or to sorbed water molecules on the wall. The neutron contrast-matching point between the TiO2 matrix and the pores filled with liquid H2O/D2O mixtures was 51/49%(v/v) H2O/D2O, yielding an estimated mass density of 3.32 g cm3. The specific surface area of the sample derived from the (U)SANS data was around 939 1003 m2 cm3 (283 302 m2 g1).

  20. The pore wall structure of porous semi-crystalline anatase TiO2

    SciTech Connect (OSTI)

    Kim, Dr Man-Ho [National Institute of Standards and Technol/University of Maryland, College Park; Doh, Dr. Jeong-Mann [Harbin Institute of Technology & Korea Institute of Science and Technology; Han, Seong Chul [Harbin Institute of Technology & Korea Institute of Science and Technology; Chae, Keun Hwa [Harbin Institute of Technology & Korea Institute of Science and Technology; Yu, Byung-Yong [Harbin Institute of Technology & Korea Institute of Science and Technology; Hong, Kyung Tea [Harbin Institute of Technology & Korea Institute of Science and Technology; Jackson, Andrew [NIST Center for Neutron Research (NCRN), Gaithersburg, MD; Anovitz, Lawrence {Larry} M [ORNL

    2011-01-01

    The structure of porous TiO2 prepared by electrochemical anodization in a fluoride-containing ethylene glycol electrolyte solution was quantitatively studied using small angle neutron scattering (SANS) and ultra small angle neutron scattering (USANS). The cylindrical pores along the coaxial direction were somewhat irregular shape, were broadly distributed in diameter, and seemed to have a broadly pseudo-hexagonal arrangement. The scattering from the pore wall showed a negative deviation from Porod scattering, indicating the interface between TiO2 and the pore was not sharp. A density gradient of around 40 ~ 60 at the pore wall (i.e. interface between the pore and the TiO2 matrix) was estimated using both constant and semi-sigmoidal interface models. This may be due to the presence of fluorine and carbon partially absorbed by the pore wall from the fluoride-containing electrolyte and sorbed water molecules on the wall. The neutron contrast-matching point between the TiO2 matrix and the pores filled with liquid H2O/D2O mixtures was 51/49 vol/vol H2O/D2O, yielding an estimated mass density of 3.32 g/cm3. The specific surface area of the sample derived from the (U)SANS data, S/V, was around 939 ~ 1003 m2/cm3 (283~ 302m2/g).

  1. Optical excitations of metallic nanoclusters buried in TiO2 for solar photochemistry

    E-Print Network [OSTI]

    the absorption of the solar spectrum by through utilizing their plasmon resonances. One challengeOptical excitations of metallic nanoclusters buried in TiO2 for solar photochemistry Fei WangV range, a much better match to the solar spectrum than the 3.8 eV Ag plasmon. AFM measurements indicate

  2. Formation of CO precursors during char gasification with O2, CO2 and H2O

    E-Print Network [OSTI]

    Truong, Thanh N.

    Formation of CO precursors during char gasification with O2, CO2 and H2O Alejandro Montoya a are presented to get insight into an unified mechanism of uncatalyzed carbon gasification. D 2002 Elsevier Science B.V. All rights reserved. Keywords: Gasification; Chemisorption; Molecular simulation; Surface

  3. Photophysics of O2 excited by tunable laser radiation around 193 nm B. L. G. Bakkera)

    E-Print Network [OSTI]

    Nijmegen, University of

    Photophysics of O2 excited by tunable laser radiation around 193 nm B. L. G. Bakkera) and D. H and the velocity map imaging technique. Angular and kinetic energy distributions of the product O ions and O(3 P2 by tunable radiation around 193 nm, a wavelength falling within the Schumann­Runge bands,1 the dominant

  4. High Energy Density Cathode for Lithium Batteries: From LiCoO_(2) to Sulfur 

    E-Print Network [OSTI]

    Pu, Xiong

    2014-05-29

    be viable. This dissertation, motivated with these aims, investigated both Li-ion batteries and Li-S batteries. LiCoO_(2), though it has been commercialized in Li-ion batteries, still has the potential to achieve higher energy density, since its practical...

  5. Hydroxyl-Quenching Effects on the Photoluminescence Properties of SnO2:Eu3+ Nanoparticles

    E-Print Network [OSTI]

    Park, Byungwoo

    Hydroxyl-Quenching Effects on the Photoluminescence Properties of SnO2:Eu3+ Nanoparticles Taeho: January 20, 2007 The effects of hydroxyl quenching were examined on the photoluminescence properties of Sn, and this behavior with XPS confirmed the hydroxyl-quenching effect. Introduction For display devices, such as plasma

  6. Calculation of TiO2 Surface and Subsurface Oxygen Vacancy by the Screened Exchange Functional

    E-Print Network [OSTI]

    Li, Hongfei; Guo, Yuzheng; Robertson, John

    2015-07-20

    . M.; Lu, G. Q., Anatase TiO2 Single Crystals with a Large Percentage of Reactive Facets. Nature 2008, 453, 638-641. 14 Thomas, A. G.; Flavell, W. R.; Mallick, A. K.; Kumarasinghe, A. R.; Tsoutsou, D.; Khan, N.; Chatwin, C.; Rayner, S.; Smith, G. C...

  7. Preparation of Size-Controlled TiO2 Nanoparticles and Derivation of Optically Transparent Photocatalytic

    E-Print Network [OSTI]

    Kim, Sang Kyu

    for controlling the size of individual particles and for obtaining the stabilized colloidal suspensions. TiO2, and the long-term stability of the suspension without ag- glomeration or precipitation is prerequisite alkoxide stabilized in acidic ethanol/water solution. The sizes of particles have been controlled

  8. Carbon Nitride-TiO2 Hybrid Modified with Hydrogenase for Visible Light Driven Hydrogen Production

    E-Print Network [OSTI]

    Caputo, Christine A.; Wang, Lidong; Beranek, Radim; Reisner, Erwin

    2015-06-29

    5.8 × 105 mol H2 (mol H2ase)–1 after 72 h in a sacrificial electron donor solution at pH 6 during solar AM 1.5G irradiation. An external quantum efficiency up to 4.8 % for photon to hydrogen conversion was achieved. The CNx-TiO2-H2ase construct...

  9. Mechanism of O2 Activation and Methanol Production by (Di(2-pyridyl)methanesulfonate)PtII

    E-Print Network [OSTI]

    Goddard III, William A.

    Mechanism of O2 Activation and Methanol Production by (Di(2- pyridyl)methanesulfonate)PtII Me observed for the SN2 functionalization to form methanol by two isomeric (dpms)PtIV Me(OH)2 complexes, one conversion of methane to methanol at low temper- ature is crucial for transportation of shale gas produced

  10. SnO2 Filled Mesoporous Tin Phosphate High Capacity Negative Electrode for Lithium Secondary Battery

    E-Print Network [OSTI]

    Cho, Jaephil

    SnO2 Filled Mesoporous Tin Phosphate High Capacity Negative Electrode for Lithium Secondary Battery insulators, and optics.1-6 On the other hand, their applications to electrode materials in lithium secondary batteries have received little attention because of the very limited candidates.7,8 Recently

  11. Graphene arch gate SiO2 shell silicon nanowire core field effect transistors

    E-Print Network [OSTI]

    Hwang, Sung Woo

    graphene into more complementary metal oxide semiconductor (CMOS)-friendly architectures. FurthermoreGraphene arch gate SiO2 shell silicon nanowire core field effect transistors J. E. Jin, J. H. Lee) metal-semiconductor field-effect transistors on single-crystal -Ga2O3 (010) substrates Appl. Phys. Lett

  12. Oxygen-tolerant proton reduction catalysis: much O_2 about nothing?

    E-Print Network [OSTI]

    Wakerley, David W.; Reisner, Erwin

    2015-05-29

    - based system that drove photocatalysis of 1A could be a result of O2? ? formation with concomitant desorption or decomposition of the Ru dye or catalyst.87 Following on from the cobaloxime system, a Co corrole catalyst synthesised by the Dey group...

  13. Inorganic-modified semiconductor TiO2 nanotube arrays for photocatalysis

    E-Print Network [OSTI]

    Lin, Zhiqun

    Inorganic-modified semiconductor TiO2 nanotube arrays for photocatalysis Mengye Wang,ab James Ioccozia,b Lan Sun,*a Changjian Lin*a and Zhiqun Lin*b Semiconductor photocatalysis is a promising resistance, and nontoxicity. This Review briefly introduces the key mechanisms of photocatalysis, highlights

  14. Direct Evidence of Lithium-Induced Atomic Ordering in Amorphous TiO2 Nanotubes

    SciTech Connect (OSTI)

    Gao, Qi; Gu, Meng; Nie, Anmin; Mashayek, Farzad; Wang, Chong M.; Odegard, Gregory M.; Shahbazian-Yassar, Reza

    2014-01-27

    In this paper, we report the first direct chemical and imaging evidence of lithium-induced atomic ordering in amorphous TiO2 nanomaterials and propose new reaction mechanisms that contradict the many works in the published literature on the lithiation behavior of these materials. The lithiation process was conducted in situ inside an atomic resolution transmission electron microscope. Our results indicate that the lithiation started with the valence reduction of Ti4+ to Ti3+ leading to a LixTiO2 intercalation compound. The continued intercalation of Li ions in TiO2 nanotubes triggered an amorphous to crystalline phase transformation. The crystals were formed as nano-islands and identified to be Li2Ti2O4 with cubic structure (a = 8.375 Å). The tendency for the formation of these crystals was verified with density functional theory (DFT) simulations. The size of the crystalline islands provides a characteristic length scale (?5 nm) at which the atomic bonding configuration has been changed within a short time period. This phase transformation is associated with local inhomogeneities in Li distribution. On the basis of these observations, a new reaction mechanism is proposed to explain the first cycle lithiation behavior in amorphous TiO2 nanotubes.

  15. EPR Study of the Surface Characteristics of Nanostructured TiO2 under UV Irradiation

    E-Print Network [OSTI]

    EPR Study of the Surface Characteristics of Nanostructured TiO2 under UV Irradiation Juan M irradiation in a vacuum show some Ti3+ centers. In contrast, under these conditions only weak signals activated by UV irradiation.1,2 However, reduced quantum yields, along with the gen- eration of undesired

  16. Rapid construction of TiO2 aggregates using microwave assisted synthesis and its application for

    E-Print Network [OSTI]

    Cao, Guozhong

    Rapid construction of TiO2 aggregates using microwave assisted synthesis and its application for dye-sensitized solar cells Xuyang Wang,a Jianjun Tian,*a Chengbin Fei,b Lili Lv,a Yajie Wangb, with a size of $500 nm have been synthesized by a microwave assisted method at 150 C in a short time ($10

  17. Effect of Niobium on the Defect Chemistry and Oxidation Kinetics of Tetragonal ZrO2

    E-Print Network [OSTI]

    Yildiz, Bilge

    of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge transport limits the oxidation kinetics. 1. INTRODUCTION Zirconia (ZrO2) is among the most important metal-6 Furthermore, zirconia is used in biomedical hip implants7 and dental restorations8 and recently

  18. Request for Alternative Commencement Site (Form O-2 Undergraduate Associate Students Only)

    E-Print Network [OSTI]

    Maroncelli, Mark

    Request for Alternative Commencement Site (Form O-2 Undergraduate Associate Students Only will be forwarded to the Graduation Coordinator in the Dean's Office of the alternative site College for their approval. The alternative site College being asked to consider this request reserves the right to approve

  19. Enhanced Photovoltaic Performance of Nanostructured Hybrid Solar Cell Using Highly Oriented TiO2 Nanotubes

    E-Print Network [OSTI]

    Cao, Guozhong

    -called third generation of solar cells including dye-sensitized solar cells, DSCs2,3 and organic phoEnhanced Photovoltaic Performance of Nanostructured Hybrid Solar Cell Using Highly Oriented TiO2- tovoltaics, OPVs.4-6 OPVs or polymer-based photovoltaic devices can be processed from solution and have

  20. O2 constraints from Paleoproterozoic detrital pyrite and uraninite Jena E. Johnson1,

    E-Print Network [OSTI]

    Fischer, Woodward

    , California Institute of Technology, Pasadena, California 91125, USA 2 Department of Geology, Occidental College, 1600 Campus Road, Los Angeles, California 90041, USA ABSTRACT Redox-sensitive detrital grains are rapidly chemically weathered within short transport distances. Prior to the rise of oxygen, low O2

  1. Hierarchically structured TiO2 for Ba-filled skutterudite with enhanced thermoelectric

    E-Print Network [OSTI]

    Cao, Guozhong

    Hierarchically structured TiO2 for Ba-filled skutterudite with enhanced thermoelectric performance be considered. Thermoelectric (TE) materials are a very good candidate to achieve a more efficient usage performance of a thermoelectric material is governed by its power factor P ¼ S2 s. The challenge to develop

  2. Photoelectrochemical hydrogen production from water/ methanol decomposition using Ag/TiO2 nanocomposite

    E-Print Network [OSTI]

    coal and gasoline [3]. Moreover, hydrogen can be used in fuel cells to generate electricity, or directly as a transportation fuel [4]. Hydrogen can be generated from hydrocarbons and water resources are low cost, environmentally friendly, high efficiency and stability. TiO2 is a strong candidate due

  3. Probing the Failure Mechanism of SnO2 Nanowires for Sodium-ion Batteries

    SciTech Connect (OSTI)

    Gu, Meng; Kushima, Akihiro; Shao, Yuyan; Zhang, Jiguang; Liu, Jun; Browning, Nigel D.; Li, Ju; Wang, Chong M.

    2013-09-30

    Non-lithium metals such as sodium have attracted wide attention as a potential charge carrying ion for rechargeable batteries, performing the same role as lithium in lithium- ion batteries. As sodium and lithium have the same +1 charge, it is assumed that what has been learnt about the operation of lithium ion batteries can be transferred directly to sodium batteries. Using in-situ TEM, in combination with DFT calculations, we probed the structural and chemical evolution of SnO2 nanowire anodes in Na-ion batteries and compared them quantitatively with results from Li-ion batteries [Science 330 (2010) 1515]. Upon Na insertion into SnO2, a displacement reaction occurs, leading to the formation of amorphous NaxSn nanoparticles covered by crystalline Na2O shell. With further Na insertion, the NaxSn core crystallized into Na15Sn4 (x=3.75). Upon extraction of Na (desodiation), the NaxSn core transforms to Sn nanoparticles. Associated with a volume shrinkage, nanopores appear and metallic Sn particles are confined in hollow shells of Na2O, mimicking a peapod structure. These pores greatly increase electrical impedance, therefore naturally accounting for the poor cyclability of SnO2. DFT calculations indicate that Na+ diffuses 30 times slower than Li+ in SnO2, in agreement with in-situ TEM measurement. Insertion of Na can chemo-mechanically soften the reaction product to greater extent than in lithiation. Therefore, in contrast to the lithiation of SnO2, no dislocation plasticity was seen ahead of the sodiation front. This direct comparison of the results from Na and Li highlights the critical role of ionic size and electronic structure of different ionic species on the charge/discharge rate and failure mechanisms in these batteries.

  4. In vitro biocompatibility study of nano TiO2 materials , Y.D. Wang2,b

    E-Print Network [OSTI]

    Zheng, Yufeng

    Company, LTD. TiO2 nanotube, with mean diameter 20nm, was provided by Department of Physics, HongkongIn vitro biocompatibility study of nano TiO2 materials W. Han1, a , Y.D. Wang2,b and Y.F. Zheng3,c yfzheng@pku.edu.cn Keywords: nano TiO2, in vitro, biocompatibility, cell proliferation, cell apoptosis

  5. Role of Benzyl Alcohol in Controlling the Growth of TiO2 on Carbon Nanotubes David J. Cooke,*,

    E-Print Network [OSTI]

    Elliott, James

    Role of Benzyl Alcohol in Controlling the Growth of TiO2 on Carbon Nanotubes David J. Cooke) in the morphological control of the growth of TiO2 on carbon nanotubes (CNTs) by the consideration of two model systems of thin-film TiO2.14,15 Kongkanand et al. reported that combining single-wall carbon nanotubes (SWCNTs

  6. Two-stage epitaxial growth of vertically-aligned SnO2 nano-rods on(001) ceria

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Solovyov, Vyacheslav F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wu, Li-jun [Brookhaven National Lab. (BNL), Upton, NY (United States); Rupich, Martin W. [American Superconductor, Devens, MA (United States); Sathyamurthy, Srivatsan [American Superconductor, Devens, MA (United States); Li, Xiaoping [American Superconductor, Devens, MA (United States); Li, Qiang [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-12-01

    Growth of high-aspect ratio oriented tin oxide, SnO2, nano-rods is complicated by a limited choice of matching substrates. We show that a (001) cerium oxide, CeO2, surface uniquely enables epitaxial growth of tin-oxide nano-rods via a two-stage process. First, (100) oriented nano-wires coat the ceria surface by lateral growth, forming a uniaxially-textured SnO2 deposit. Second, vertical SnO2nano-rods nucleate on the deposit by homoepitaxy. We demonstrate growth of vertically oriented 1-2 ?m long nano-rods with an average diameter of ?20 nm.

  7. PET exam A 424304 20-032013 Short answers 111. Ex = Ex (O2) + Ex(N2) + Ex (unmix)

    E-Print Network [OSTI]

    Zevenhoven, Ron

    (303/293)+8,314*293*ln(5) = 2288,6 W Similar Ex (N2) = 3709,8 W, and Ex (unmix) = 3478,1 W Total = 9475PET exam ÅA 424304 20-032013 Short answers 111. Ex = Ex (O2) + Ex(N2) + Ex (unmix) Ex (O2) = (O2 --- Similar for N2. Ex (unmix) = · -R·T·(0.21ln0.21 + 079ln0.79) Ex (O2) = (2100/3600)*(29,4*10-293*29,4*ln

  8. Efficiency of clay-TiO2 nanocomposites on the photocatalytic elimination of a model hydrophobic air pollutant

    E-Print Network [OSTI]

    Kibanova, Daria

    2010-01-01

    of semiconductor photocatalysis Chem. Rev. 1995, 95, 69-effluents by TiO 2 photocatalysis Catalysis Today 2000, 63,clay on adsorption and photocatalysis of gaseous molecules

  9. Compact Electrochemical Bi-functional NOx/O2 Sensors with an Internal Reference for High Temperature Applications

    Broader source: Energy.gov [DOE]

    A inexpensive compact O2 sensor has been developed using internal reference gas that is stable for months, has no complex electronics, and is amenable to mass production

  10. Two-stage epitaxial growth of vertically-aligned SnO2 nano-rods on(001) ceria

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Solovyov, Vyacheslav F.; Wu, Li-jun; Rupich, Martin W.; Sathyamurthy, Srivatsan; Li, Xiaoping; Li, Qiang

    2014-09-20

    Growth of high-aspect ratio oriented tin oxide, SnO2, nano-rods is complicated by a limited choice of matching substrates. We show that a (001) cerium oxide, CeO2, surface uniquely enables epitaxial growth of tin-oxide nano-rods via a two-stage process. First, (100) oriented nano-wires coat the ceria surface by lateral growth, forming a uniaxially-textured SnO2 deposit. Second, vertical SnO2nano-rods nucleate on the deposit by homoepitaxy. We demonstrate growth of vertically oriented 1-2 ?m long nano-rods with an average diameter of ?20 nm.

  11. Current-Controlled Negative Differential Resistance due to Joule Heating in TiO2

    E-Print Network [OSTI]

    A. S. Alexandrov; A. M. Bratkovsky; B. Bridle; S. E. Savel'ev; D. B. Strukov; R. Stanley Williams

    2011-08-15

    We show that Joule heating causes current-controlled negative differential resistance (CC-NDR) in TiO2 by constructing an analytical model of the voltage-current V(I) characteristic based on polaronic transport for Ohm's Law and Newton's Law of Cooling, and fitting this model to experimental data. This threshold switching is the 'soft breakdown' observed during electroforming of TiO2 and other transition-metal-oxide based memristors, as well as a precursor to 'ON' or 'SET' switching of unipolar memristors from their high to their low resistance states. The shape of the V(I) curve is a sensitive indicator of the nature of the polaronic conduction.

  12. Aggregated TiO2 Based Nanotubes for Dye Sensitized Solar Cells

    SciTech Connect (OSTI)

    Nie, Zimin; Zhou, Xiaoyuan; Zhang, Qifeng; Cao, Guozhong; Liu, Jun

    2013-11-01

    One-dimensional (1D) semiconducting oxides have attracted great attention for dye sensitized solar cells (DSCs), but the overall performance is still quite limited as compared to TiO2 nanocrystalline DSCs. Here, we report the synthesis of aggregated TiO2 based nanotubes with controlled morphologies and crystalline structures to obtain an overall power conversion efficiency of 9.9% using conventional dye without any additional chemical treatment steps. The high efficiency is attributed to the unique aggregate structure for light harvesting, optimized high surface area, and good crystallinity of the nanotube aggregates obtained through proper thermal annealing. This study demonstrates that high efficiency DSCs can be obtained with 1D nanomaterials, and provides lessons on the importance of optimizing both the nanocrystalline structure and the overall microscale morphology.

  13. Reactivity and reaction intermediates for acetic acid adsorbed on CeO2(111)

    SciTech Connect (OSTI)

    Calaza, Florencia; Chen, Tsung-Liang; Mullins, David R; Xu, Ye; Overbury, Steven {Steve} H

    2015-01-01

    Adsorption and reaction of acetic acid on a CeO2(1 1 1) surface was studied by a combination of ultra-highvacuum based methods including temperature desorption spectroscopy (TPD), soft X-ray photoelectronspectroscopy (sXPS), near edge X-ray absorption spectroscopy (NEXAFS) and reflection absorption IRspectroscopy (RAIRS), together with density functional theory (DFT) calculations. TPD shows that thedesorption products are strongly dependent upon the initial oxidation state of the CeO2surface, includingselectivity between acetone and acetaldehyde products. The combination of sXPS and NEXAFS demon-strate that acetate forms upon adsorption at low temperature and is stable to above 500 K, above whichpoint ketene, acetone and acetic acid desorb. DFT and RAIRS show that below 500 K, bridge bondedacetate coexists with a moiety formed by adsorption of an acetate at an oxygen vacancy, formed bywater desorption.

  14. Probing the photochemistry of chemisorbed oxygen on TiO2(110) with Kr and other co-adsorbates

    SciTech Connect (OSTI)

    Petrik, Nikolay G.; Kimmel, Gregory A.

    2014-02-14

    Weakly bound (physisorbed) atoms and molecules such as Ar, Kr, Xe, CO, CH4, CH3OH, CO2 and N2 are used to probe the photochemical interactions of O2 on rutile TiO2(110). UV irradiation of chemisorbed O2 along with the physisorbed probe species leads to photon-stimulated desorption (PSD) of Ar, Kr, CO, CH4 and N2. Without co-adsorbed O2, the PSD yields of the probe species are very low or not observed. No PSD was observed for CO2, N2O, CH3OH and the PSD yield for Xe is very low compared to the other probe atoms or molecules. The angular distribution of the photo-desorbing Kr, which is broad and cosine, is quite different from the O2 PSD angular distribution, which is sharply peaked along the surface normal. The Kr PSD yields increase with increasing coverage of Kr and of chemisorbed O2. We propose a mechanism for the observed phenomena where the chemisorbed O2 serves as photoactive center, excited via electronic excitations (electrons and/or holes) created in the TiO2 substrate by UV photon irradiation. The photo-excited O2 may transfer its energy to neighboring co-adsorbed atom or molecule resulting in desorption of the latter. Simple momentum transfer considerations suggest that heavier adsorbates (like Xe) and adsorbates with higher binding energy (like CO2) should desorb less efficiently according to the proposed mechanism. Various forms of chemisorbed O2 appeared photoactive in such stimulated desorption of Kr atoms: molecular anions (O22-, O2-), adatoms (Oa), and others. The observed phenomenon provides a new tool for study of photocatalysis.

  15. Aligned Epitaxial SnO2 Nanowires on Sapphire: Growth and Device Applications Supporting

    E-Print Network [OSTI]

    Zhou, Chongwu

    maximum tube furnace from Lindberg/Blue M with a ramping rate of 23°C/min. An 1100°C one-inch tube furnace-inch furnace to complete a thermal de-wetting step at 800°C for 15 minutes in ambient air. The synthesis of aligned SnO2 nanowires was carried out in a horizontal quartz tube in the one-inch furnace. The Sn powder

  16. Relaxation of 2+1 dimensional classical O(2) symmetric scalar fields

    E-Print Network [OSTI]

    Borsanyi, S; Borsanyi, Sz.; Szep, Zs.

    2001-01-01

    Real time thermalization and relaxation phenomena are studied in the low energy density phase of the 2+1 dimensional classical O(2) symmetric scalar theory by solving numerically its dynamics. The near-equilibrium decay rate of on-shell waves and the power law governing the large time asymptotics of the off-shell relaxation agree with the analytic results based on linear response theory. The realisation of the Mermin-Wagner theorem is also studied in the final equilibrium ensemble.

  17. Electron-Stimulated Reactions and O-2 Production in Methanol-Covered Amorphous Solid Water Films

    SciTech Connect (OSTI)

    Akin, Minta C.; Petrik, Nikolay G.; Kimmel, Gregory A.

    2009-03-14

    The low-energy, electron-stimulated desorption (ESD) of molecular products from amorphous solid water (ASW) films capped with methanol is investigated versus methanol coverage (0 - 4 x 1015 cm-2) at 50 K using 100 eV incident electrons. The major ESD products from a monolayer of methanol on ASW are quite similar to the ESD products from bulk methanol film: H2, CH4, H2O, C2H6, CO, CH2O, and CH3OH. For 40 ML ASW films, the molecular oxygen, hydrogen, and water ESD yields from the ASW are suppressed with increasing methanol coverage, while the CH3OH ESD yield increases proportionally to the methanol coverage. The suppression of the water ESD products by methanol is consistent with the non-thermal reactions occurring preferentially at or near the ASW/vacuum interface and not in the interior of the film. The water and molecular hydrogen ESD yields from the water layer decrease exponentially with the methanol cap coverage with 1/e constants of ~ 0.6 x 1015 cm-2 and 1.6 x 1015 cm-2, respectively. In contrast, the O2 ESD from the water layer is very efficiently quenched by small amounts of methanol (1/e ~ 6.5 x 1013 cm-2). The rapid suppression of O2 production by small amounts of methanol is due to reactions between CH3OH and the precursors for the O2 - mainly OH radicals. A kinetic model for the O2 ESD which semi-quantitatively accounts for the observations is presented.

  18. Non-thermal Plasma - Nanometer TiO2 Photocatalysis for Formaldehyde Decomposition 

    E-Print Network [OSTI]

    Yuan, Q.; Feng, G.; Guang, X.

    2006-01-01

    for the carcinogenicity, the allergy source which is commonly recognized, and one of the latent sudden-change leading matters by the World Health Organization. Therefore, indoor pollutant purification is imperative. At present, the indoor pollutant purification... is more promising. Key words: Air cleaning Techonlogy; Non-thermal Plasma; TiO2 Photocatalysis 1. INTRODUCTION The volatile organic matter (VOCs) [ 1 ]is the main pollution source of indoor air, also the toxicity is extremely big, can lead...

  19. Atomistic Studies of Cation Transport in Tetragonal ZrO2 During Zirconium Corrosion

    SciTech Connect (OSTI)

    Xian-Ming Bai; Yongfeng Zhang; Michael R. Tonks

    2013-10-01

    Zirconium alloys are the major fuel cladding materials in current reactors. The water-side corrosion is one of the major degradation mechanisms of these alloys. During corrosion the transport of oxidizing species in zirconium dioxide (ZrO2) determines the corrosion kinetics. Previously it has been argued that the outward diffusion of cation ions is important for forming protective oxides. In this work, the migration of Zr defects in tetragonal ZrO2 is studied with temperature accelerated dynamics and molecular dynamics simulations. The results show that Zr interstitials have anisotropic diffusion and migrate preferentially along the [001] or c direction in tetragonal ZrO2. The compressive stresses can increase the Zr interstitial migration barrier significantly. The migration barriers of some defect clusters can be much lower than those of point defects. The migration of Zr interstitials at some special grain boundaries is much slower than in a bulk oxide. The implications of these atomistic simulation results in the Zr corrosion are discussed.

  20. Valence electronenergy-lossspectroscopystudyofZrSiO4 and ZrO2

    SciTech Connect (OSTI)

    Spence, John; Jiang, Nan

    2013-07-01

    ZrSiO4 (zircon) and m-ZrO2 (zirconia) are fundamental and industrially important materials.This work reports the detailed valence electron energy-loss spectroscopy (VEELS) studies of these compounds. The dielectric response functions, as well as single-electron interband transition spectra,are derived from VEELS data for both ZrSiO4 and m-ZrO2, in the rang e5–50 eV using the Kramers–Kronig analysis method. Our interpretation of the interband transitions is given with the aid of ab initio calculations of density of states. The bandgap energies for both materials are also measured using VEELS.The surface and bulk plasmons are identified: the surface plasmon peaks locate at around 12 eV,and two bulk plasmon peaks are ~15–16 eV and ~25–27 eV,respectively.Although similarities in the VEELS exist between ZrSiO4 and m-ZrO2, two majo rdifferences are als onoticed and explained in terms of composition and structure differences.

  1. 19.2% Efficient InP Heterojunction Solar Cell with Electron-Selective TiO2 Contact

    E-Print Network [OSTI]

    Javey, Ali

    19.2% Efficient InP Heterojunction Solar Cell with Electron-Selective TiO2 Contact Xingtian Yin for solar energy conversion.20 The most efficient InP solar cells use a homojunction configurationP to form a heterojunction solar cell with an efficiency of 17.4%.23,24 Here, by employing a TiO2 electron

  2. The electrochemical reactions of SnO2 with Li and Na: a study using thin films and mesoporous carbons

    SciTech Connect (OSTI)

    Gorka, Joanna [ORNL; Baggetto, Loic [ORNL; Keum, Jong Kahk [ORNL; Mahurin, Shannon Mark [ORNL; Mayes, Richard T [ORNL; Dai, Sheng [ORNL; Veith, Gabriel M [ORNL

    2015-01-01

    In this work we have determined the room temperature electrochemical reactivity of SnO2 thin films and mesoporous carbons filled with SnO2 anodes with Na, and compare the results with those obtained during the reaction with Li. We show that SnO2 can reversibly deliver up to 6.2 Li/SnO2 whereas the reaction with Na is significantly limited. The initial discharge capacity is equivalent to less than 4 Na/SnO2, which is expected to correspond to the formation of 2 Na2O and Sn. This limited discharge capacity suggests the negative role of the formed Na2O matrix upon the reversible reaction of Sn clusters. Moreover, the reversible cycling of less than 1 Na/SnO2, despite the utilization of 6-7 nm SnO2 particles, is indicative of sluggish reaction kinetics. The origin of this significant capacity reduction is likely due to the formation of a diffusion limiting interface. Furthermore, there is a larger apparent hysteresis compared to Li. These results point to the need to design composite structures of SnO2 nanoparticles with suitable morphological and conductivity components.

  3. O2 Reduction on Graphite and Nitrogen-Doped Graphite: Experiment and Theory Reyimjan A. Sidik and Alfred B. Anderson*

    E-Print Network [OSTI]

    Popov, Branko N.

    toward NOx reduction.7,8 Others are oxidation catalysts.9 In the case of NOx oxidation and O2 reductionO2 Reduction on Graphite and Nitrogen-Doped Graphite: Experiment and Theory Reyimjan A. Sidik for reduction of approximately 0.5 V (SHE) compared to the onset potential of 0.2 V observed for untreated

  4. Performance of Gd-doped Ti-based Sb-SnO2 anodes for electrochemical destruction of phenol

    E-Print Network [OSTI]

    O2 anodes (Ti/SnO2-Sb), based on their electro-catalytic activities and organic oxidation rates (Ko Available online 24 October 2007 Abstract The performance of electrodes for the electro-catalytic the elec- tro-catalytic characteristics and stability of the electrodes. Some researchers have found

  5. Effects of O2 Concentration on the Rate and Selectivity in Oxidative Dehydrogenation of Ethane Catalyzed by Vanadium Oxide

    E-Print Network [OSTI]

    Iglesia, Enrique

    Effects of O2 Concentration on the Rate and Selectivity in Oxidative Dehydrogenation of Ethane monovanadates. Cofeed and staged-O2 introduction modes led to similar ethane dehydrogenation and combustion introduced gradually as ethane conversion increased. These effects reflect inhibition of homogeneous ethene

  6. TiO2 Polymer Nanocomposites In conjunction with Dr. Ashok Kumar in the Mechanical Engineering Department at

    E-Print Network [OSTI]

    Harmon, Julie P.

    TiO2 Polymer Nanocomposites In conjunction with Dr. Ashok Kumar in the Mechanical Engineering and Engineering, C 23, 737 (2003). 17. "Polymer-TiO2 Nanocomposites: A route Towards Visually Transparent Broadband UV filters and High Refractive Index Materials", Macromolecular Materials Engineering, 288, 44

  7. Mechanism of Electron-Induced Hydrogen Desorption from Hydroxylated Rutile TiO2 (110) D. P. Acharya,

    E-Print Network [OSTI]

    Ciobanu, Cristian

    Mechanism of Electron-Induced Hydrogen Desorption from Hydroxylated Rutile TiO2 (110) D. P. Acharya electrons with controlled energy and flux into single surface hydroxyls (OH) in cryogenic scanning tunneling on the bridging oxygen (Obr) rows on TiO2(110) generates a bridge-bonded hydroxyl (OHbr), has received attention

  8. Chemically grown TiO2 on glass with superior photocatalytic properties G. Kenanakis a,b,

    E-Print Network [OSTI]

    : Titanium dioxide thin films Degussa P25 TiO2 Sol­gel technique Photocatalysis Stearic acid Methylene blue of photocatalysis for various applications such as water treatment, air purification and fuel cells [1­5]. TiO2

  9. Improved Lithium Ion Behavior Properties of TiO2@Graphitic-like Carbon Core@Shell Nanostructure

    E-Print Network [OSTI]

    Cao, Guozhong

    Improved Lithium Ion Behavior Properties of TiO2@Graphitic-like Carbon Core@Shell Nanostructure Min Intercalation Electrochemistry Capacitance Lithium Ion batteries A B S T R A C T We demonstrate TiO2@graphitic on the electrode surface and enhanced lithium ion intercalation, leading to lower charge transfer resistance

  10. Three-dimensional morphology evolution of SiO2 patterned films under MeV ion irradiation

    E-Print Network [OSTI]

    Hutchinson, John W.

    Three-dimensional morphology evolution of SiO2 patterned films under MeV ion irradiation Kan OtaniO2 stripes on Si substrates induced by 3 MeV O++ ion irradiation. We develop a 3D constitutive evolution in complex three-dimensional structures under MeV ion irradiation. © 2006 American Institute

  11. Dye Surface Coating Enables Visible Light Activation of TiO2 Nanoparticles Leading to Degradation of

    E-Print Network [OSTI]

    Brown, Eric

    Dye Surface Coating Enables Visible Light Activation of TiO2 Nanoparticles Leading to Degradation that an alizarin red S ~ARS! dye coating on TiO2 nanoparticles enables visible light activation of reactive oxygen species. Successful coating of nanoparti- cles with dye is demonstrated through

  12. Preparation and characterization of VOx/TiO2 catalytic coatings on stainless steel plates for structured catalytic reactors.

    E-Print Network [OSTI]

    Boyer, Edmond

    1 Preparation and characterization of VOx/TiO2 catalytic coatings on stainless steel plates are used in the mild oxidation of hydrocarbons and NOx abatement are studied. Stainless steel (316 L) was chosen because of its large application in industrial catalytic reactors. TiO2 films on stainless steel

  13. High Density n-Si/n-TiO2 Core/Shell Nanowire Arrays with Enhanced Photoactivity

    SciTech Connect (OSTI)

    Hwang, Yun Jeong; Boukai, Akram; Yang, Peidong

    2008-11-15

    There are currently great needs to develop low-cost inorganic materials that can efficiently perform solar water splitting as photoelectrolysis of water into hydrogen and oxygen has significant potential to provide clean energy. We investigate the Si/TiO2 nanowire heterostructures to determine their potential for the photooxidation of water. We observed that highly dense Si/TiO2 core/shell nanowire arrays enhanced the photocurrent by 2.5 times compared to planar Si/TiO2 structure due to their low reflectance and high surface area. We also showed that n-Si/n-TiO2 nanowire arrays exhibited a larger photocurrent and open circuit voltage than p-Si/n-TiO2 nanowires due to a barrier at the heterojunction.

  14. Role of Water in Methanol Photochemistry on Rutile TiO2(110)

    SciTech Connect (OSTI)

    Shen, Mingmin; Henderson, Michael A.

    2012-08-07

    Photochemistry of the molecularly and dissociatively adsorbed forms of methanol on the vacuum-annealed rutile TiO2(110) surface was explored using temperature programmed desorption (TPD), both with and without coadsorbed water. Methoxy, and not methanol, was confirmed as the photochemically active form of adsorbed methanol on this surface. UV irradiation of methoxy-covered TiO2(110) lead to depletion of the methoxy coverage and formation of formaldehyde and a surface OH group. Coadsorbed water did not promote either molecular methanol photochemistry or thermal decomposition of methanol to methoxy. However, terminal OH groups (OHt), prepared by coadsorption of water and oxygen atoms, thermally converted molecularly adsorbed methanol to methoxy at 120 K, thus enabling photoactivity. While chemisorbed water molecules had no influence on methoxy photochemistry, water molecules hydrogen-bonded in the second layer to bridging oxygen (Obr) sites inhibited the methoxy photodecomposition to formaldehyde. From this we conclude that Obr sites accept protons from the hole-mediated conversion of methoxy to formaldehyde. These results provide new fundamental understanding of the hole-scavenging role of methanol in photochemical processes on TiO2-based materials and how water influences this photochemistry. This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle under contract DEAC05-76RL01830. The research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.

  15. Importance of Diffusion in Methanol Photochemistry on TiO2(110)

    SciTech Connect (OSTI)

    Shen, Mingmin; Acharya, Danda P.; Dohnalek, Zdenek; Henderson, Michael A.

    2012-12-06

    The photoactivity of methanol on the rutile TiO2(110) surface is shown to depend on the ability of methanol to diffuse on the surface and find sites active for its thermal dissociation to methoxy. Temperature programmed desorption (TPD) results show that the extent of methanol photodecomposition to formaldehyde is negligible on the clean TiO2(110) surface at 100 K due to a scarcity of sites that can convert (photoinactive) methanol to (photoactive) methoxy. The extent of photoactivity at 100 K significantly increases when methanol is coadsorbed with oxygen, however only those molecules able to adsorb near (next to) a coadsorbed oxygen species are active. Preannealing coadsorbed methanol and oxygen to above 200 K prior to UV irradiation results in a significant increase in photoactivity. Scanning tunneling microscopy (STM) images clearly show that the advent of increased photoactivity in TPD correlates with the onset of methanol diffusion along the surface’s Ti4+ rows at ~200 K. These results demonstrate that optimizing thermal processes (such as diffusion or proton transfer reactions) can be critical to maximizing photocatalytic reactivity on TiO2 surfaces. This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle under contract DEAC05-76RL01830. The research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.

  16. Effect of Coadsorbed Water on the Photodecomposition of Acetone on TiO2(110)

    SciTech Connect (OSTI)

    Henderson, Michael A.

    2008-06-10

    The influence of coadsorbed water on the photodecomposition of acetone on TiO2 was examined using temperature programmed desorption (TPD) and the rutile TiO2(110) surface as a model photocatalyst. Of the two major influences ascribed to water in the heterogeneous photocatalysis literature (promotion via OH radical supply and inhibition due to site blocking), only the negative influence of water was observed. As long as the total water and acetone coverage was maintained well below the first layer saturation coverage (‘1 ML’), little inhibition of acetone photodecomposition was observed. However, as the total water+acetone coverage exceeded 1 ML, acetone was preferentially displaced from the first layer to physisorbed states by water and the extent of acetone photodecomposition attenuated. The displacement originated from water compressing acetone into high coverage regions where increased acetone-acetone repulsions caused displacement from the first layer. The immediate product of acetone photodecomposition was adsorbed acetate, which occupies twice as many surface sites per molecule as compared to acetone. Since the acetate intermediate was more stable on the TiO2(110) surface than either water or acetone (as gauged by TPD) and since its photodecomposition rate was less than that of acetone, additional surface sites were not opened up during acetone photodecomposition for previously displaced acetone molecules to re-enter the first layer. Results in this study suggest that increased molecular-level repulsions between organic molecules brought about by increased water coverage are as influential in the inhibiting effect of water on photooxidation rates as are water-organic repulsions.

  17. DFT+U Study of CeO2 and Its Native Defects

    E-Print Network [OSTI]

    Huang, Bolong; Gillen, Roland; Robertson, John

    2014-10-14

    , Frenkel defect, pseudopotential transferability, oxidation catalyst 1. Introduction CeO2 is an important lanthanide oxide which is widely used as an oxygen buffer in car exhaust catalysts1, as a fast ion conductor in solid state fuel cells2, as a... as optimization of pseudopotentials47. The PBE functional was chosen for PBE+U calculations with a kinetic cutoff energy of 750eV, which expands the valence electrons states in a plane-wave basis set. The ensemble DFT (EDFT) method of Marzari et al48 is used...

  18. Modeling of durability of polyelectrolyte membrane of O2/H2 fuel cell

    E-Print Network [OSTI]

    Atrazhev, Vadim V

    2014-01-01

    In this paper, we discuss critical aspects of the mechanisms and features of polymer proton exchange membrane (PEM) degradation in low-temperature H2/O2 fuel cell. In this paper, we focused on chemical mechanism of OH radical generation and their distribution in operational fuel cell. According to the current concept, free radicals are generated from hydrogen and oxygen crossover gases at the surface of Pt particles that precipitated in the membrane. We explicitly calculate Pt precipitation rate and electrochemical potential distribution in the membrane that controls it. Based on radical generation rate and Pt distribution we calculate degradation rate of the membrane taking advantage of simple kinetics equations.

  19. Redox Active Layer-by-Layer Structures containing MnO2 Nanoparticles

    SciTech Connect (OSTI)

    Bazito, Fernanda; O'Brien, Robert; Buttry, Daniel A.

    2005-02-01

    Nanoscale materials provide unique properties that will enable new technologies and enhance older ones. One area of intense activity in which nanoscale materials are being used is in the development of new functional materials for battery applications. This effort promises superior materials with properties that circumvent many of the problems associated with traditional battery materials. Previously we have worked on several approaches for using nanoscale materials for application as cathode materials in rechargeable Li batteries. Our recent work has focused on synthesizing MnO2 nanoparticles and using these in layer-by-layer (LbL) structures to probe the redox properties of the nanoparticles. We show that the aqueous colloidal nanoparticles produced by butanol reduction of tetramethylammonium permanganate can be trapped in thin films using a layer-by-layer deposition approach, and that these films are both redox active and exhibit kinetically facile electrochemical responses. We show cyclic voltammetry of MnO2 colloidal nanoparticles entrapped in a LbL thin film at an ITO electrode surface using poly(diallyldimethylammonium chloride) (PDDA). CV experiments demonstrate that Li+ insertion accompanies Mn(IV) reduction in LiClO4 supporting electrolytes, and that reduction is hindered in supporting electrolytes containing only tetrabutylammonium cations. We also show that electron propagation through multilayer films is facile, suggesting that electrons percolate through the films via electron exchange between nanoparticles.

  20. Principles of water oxidation and O2-based hydrocarbon transformation by multinuclear catalytic sites

    SciTech Connect (OSTI)

    Musaev, Djamaladdin G [Chemistry, Emory University; Hill, Craig L [Chemistry, Emory University; Morokuma, Keiji [Chemistry, Emory University

    2014-10-28

    Abstract The central thrust of this integrated experimental and computational research program was to obtain an atomistic-level understanding of the structural and dynamic factors underlying the design of catalysts for water oxidation and selective reductant-free O2-based transformations. The focus was on oxidatively robust polyoxometalate (POM) complexes in which a catalytic active site interacts with proximal metal centers in a synergistic manner. Thirty five publications in high-impact journals arose from this grant. I. Developing an oxidatively and hydrolytically stable and fast water oxidation catalyst (WOC), a central need in the production of green fuels using water as a reductant, has proven particularly challenging. During this grant period we have designed and investigated several carbon-free, molecular (homogenous), oxidatively and hydrolytically stable WOCs, including the Rb8K2[{Ru4O4(OH)2(H2O)4}(?-SiW10O36)2]·25H2O (1) and [Co4(H2O)2(?-PW9O34)2]10- (2). Although complex 1 is fast, oxidatively and hydrolytically stable WOC, Ru is neither abundant nor inexpensive. Therefore, development of a stable and fast carbon-free homogenous WOC, based on earth-abundant elements became our highest priority. In 2010, we reported the first such catalyst, complex 2. This complex is substantially faster than 1 and stable under homogeneous conditions. Recently, we have extended our efforts and reported a V2-analog of the complex 2, i.e. [Co4(H2O)2(?-VW9O34)2]10- (3), which shows an even greater stability and reactivity. We succeeded in: (a) immobilizing catalysts 1 and 2 on the surface of various electrodes, and (b) elucidating the mechanism of O2 formation and release from complex 1, as well as the Mn4O4L6 “cubane” cluster. We have shown that the direct O-O bond formation is the most likely pathway for O2 formation during water oxidation catalyzed by 1. II. Oxo transfer catalysts that contain two proximal and synergistically interacting redox active metal centers in the active site form another part of considerable interest of our grant because species with such sites [including methane monooxygenase (MMO) and more] are some of the most effective oxygenase catalysts known. Our team conducted the following research on ?-M2-Keggin complexes: (a) investigated stability of the trimer [{Fe3(OH)3(H2O)2}3(?-SiW10O36)3]15-, 4, in water, and developed the chemistry and catalysis of the di-iron centered POM, [?(1,2)-SiW10{Fe(OH)}2O38]6-, 5, in organic solvents (Figure 2). We also study the thermodynamic and structural stability of ?-M2-Keggin in aqueous media for different M’s (d-electron metals). We have defined two structural classes of POMs with proximally bound d-electron metal centers. We refer to these structural isomers of the {?-M2SiW10} family of POMs as “in-pocket” and “out-of pocket”. We have elucidated the factors controlling the structure and stability of the V, Fe, Ru, Tc, Mo and Rh derivatives of [(SiO4)M2(OH)2W10O32]4- using a range of computational tools. We have: (a) demonstrated that heteroatom X in these polyanions may function as an “internal switch” for defining the ground electronic states and, consequently, the reactivity of the ?-M2-Keggin POM complexes; (b) elucidated reactivity of divacant lacunary species and polyperoxotungstates (PPTs), {Xn+O4[WO(O2)2]4}n-, which could be degradation products of ?-M2-Keggin complexes in aqueous media; (c) elucidated the role of the POM ligand in stabilization of {Ru2} and {(Ru-oxo)2} fragments in the reactant and product of the reaction of {?-[(Xn+O4)Ru2(OH)2W10O32]}(8-n)- (where X = Si4+, P5+ and S6+) with O2, and (d) the mechanisms of olefin epoxidation catalyzed by these di-d-transition metal substituted and divacant lacunary ?-M2-Keggin complexes. III. Complementing the efforts presented above was the development of less time-consuming but reasonably accurate computational methods allowing one to explore more deeply large catalytic systems. We developed Reactive Force Field (ReaxFF) to study interaction of the targeted POMs with water, pro

  1. On the consistency of QCBED structure factor measurements for TiO2 (Rutile)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jiang, Bin; Zuo, Jian -Min; Friis, Jesper; Spence, John C. H.

    2003-09-16

    The same Bragg reflection in TiO2 from twelve different CBED patterns (from different crystals, orientations and thicknesses) are analysed quantitatively in order to evaluate the consistency of the QCBED method for bond-charge mapping. The standard deviation in the resulting distribution of derived X-ray structure factors is found to be an order of magnitude smaller than that in conventional X-ray work, and the standard error (0.026% for FX(110)) is slightly better than obtained by the X-ray Pendellosung method applied to silicon. This is sufficiently accuracy to distinguish between atomic, covalent and ionic models of bonding. We describe the importance of extractingmore »experimental parameters from CCD camera characterization, and of surface oxidation and crystal shape. Thus, the current experiments show that the QCBED method is now a robust and powerful tool for low order structure factor measurement, which does not suffer from the large extinction (multiple scattering) errors which occur in inorganic X-ray crystallography, and may be applied to nanocrystals. Our results will be used to understand the role of d electrons in the chemical bonding of TiO2.« less

  2. New Insights into Reaction Mechanisms of Ethanol Steam Reforming on Co-ZrO2

    SciTech Connect (OSTI)

    Sun, Junming; Karim, Ayman M.; Mei, Donghai; Engelhard, Mark H.; Bao, Xinhe; Wang, Yong

    2015-01-01

    The reaction pathway of ethanol steam reforming on Co-ZrO2 has been identified and the active sites associated with each step are proposed. Ethanol is converted to acetaldehyde and then to acetone, followed by acetone steam reforming. More than 90% carbon was found to follow this reaction pathway. N2-Sorption, X-ray Diffraction (XRD), Temperature Programmed Reduction (TPR), in situ X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy, as well as theoretical Density Functional Theory (DFT) calculations have been employed to identify the structure and functionality of the catalysts, which was further used to correlate their performance in ESR. It was found that metallic cobalt is mainly responsible for the acetone steam reforming reactions; while, CoO and basic sites on the support play a key role in converting ethanol to acetone via dehydrogenation and condensation/ketonization reaction pathways. The current work provides fundamental understanding of the ethanol steam reforming reaction mechanisms on Co-ZrO2 catalysts and sheds light on the rational design of selective and durable ethanol steam reforming catalysts.

  3. Electrolyte Concentration Effect of a Photoelectrochemical Cell Consisting of TiO 2 Nanotube Anode

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ren, Kai; Gan, Yong X.; Nikolaidis, Efstratios; Sofyani, Sharaf Al; Zhang, Lihua

    2013-01-01

    The photoelectrochemical responses of a TiO 2 nanotube anode in ethylene glycol (EG), glycerol, ammonia, ethanol, urea, and Na 2 S electrolytes with different concentrations were investigated. The TiO 2 nanotube anode was highly efficient in photoelectrocatalysis in these solutions under UV light illumination. The photocurrent density is obviously affected by the concentration change. Na 2 S generated the highest photocurrent density at 0, 1, and 2?V bias voltages, but its concentration does not significantly affect the photocurrent density. Urea shows high open circuit voltage at proper concentration and low photocurrent at different concentrations. Externally applied bias voltage ismore »also an important factor that changes the photoelectrochemical reaction process. In view of the open circuit voltage, EG, ammonia, and ethanol fuel cells show the trend that the open circuit voltage (OCV) increases with the increase of the concentration of the solutions. Glycerol has the highest OCV compared with others, and it deceases with the increase in the concentration because of the high viscosity. The OCV of the urea and Na 2 S solutions did not show obvious concentration effect. « less

  4. In Situ Observation of the Electrochemical Lithiation of a Single SnO2 Nanowire Electrode

    SciTech Connect (OSTI)

    Huang, J. Y.; Zhong, Li; Wang, Chong M.; Sullivan, John P.; Xu, Wu; Zhang, Li Q.; Mao, Scott; Hudak, N.; Liu, Xiao H.; Subramanian, Arun Kumar; Fan, Hongyou; Qi, Liang; Kushima, Akihiro; Li, Ju

    2010-11-18

    We report the first real-time transmission electron microscopy (TEM) observations of the structural evolution and phase transformation of lithium-ion battery anode during the battery charging process. A nanobattery consisting of a single SnO2 nanowire anode and an ionic liquid electrolyte was successfully constructed in a TEM. We observed that during the charging process, the SnO2 crystal was converted to Li2O glass with LixSn nanocrystalline precipitates as the reaction front propagated progressively along the nanowire. After the reaction front passed, the nanowire showed swelling, elongation, and large off-axis distortion (spiraling). Upon completion of the electrochemical charging, the nanowire showed up to 120% elongation and a 30% increase in diameter with a volume expansion of about 272%. The charging front, which separates the reacted and unreacted sections of the nanowire, contains a high density of mobile dislocations, which are continuously nucleated and annihilated at the moving reaction front. This dislocation cloud indicates large in-plane misfit stresses, and serves as structural precursor to the eventual complete solid-state amorphization. The rate of charging in our nanobatteries is found to be proportional to the inverse square root of nanowire length, indicating that a standalone nanobattery or integrated arrays of nanobatteries should have kinetic advantage over conventional battery design. The present observations also provide important mechanistic insights for the design of advanced batteries with improved performance and lifetime for broad electrical energy storage applications.

  5. On the Consistency of QCBED Structure Factor Measurements for TiO2 (Rutile)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jiang, Bin; Zuo, Jian-Min; Friis, Jesper; Spence, John C.H.

    2003-09-16

    The same Bragg reflection in TiO2 from twelve different CBED patterns (from different crystals, orientations and thicknesses) are analysed quantitatively in order to evaluate the consistency of the QCBED method for bond-charge mapping. The standard deviation in the resulting distribution of derived X-ray structure factors is found to be an order of magnitude smaller than that in conventional X-ray work , and the standard error (0.026% for FX(110)) is slightly better than obtained by the X-ray Pendellosung method applied to silicon. This is sufficiently accuracy to distinguish between atomic, covalent and ionic models of bonding. We describe the importance of extracting experimental parameters from CCD camera characterization, and of surface oxidation and crystal shape. The current experiments show that the QCBED method is now a robust and powerful tool for low order structure factor measurement, which does not suffer from the large extinction (multiple scattering) errors which occur in inorganic X-ray crystallography, and may be applied to nanocrystals. Our results will be used to understand the role of d electrons in the chemical bonding of TiO2.

  6. Mineralization of Basalts in the CO2-H2O-SO2-O2 System

    SciTech Connect (OSTI)

    Schaef, Herbert T.; Horner, Jacob A.; Owen, Antionette T.; Thompson, Christopher J.; Loring, John S.; McGrail, B. Peter

    2014-05-01

    Sequestering carbon dioxide (CO2) containing minor amounts of co-contaminants in geologic formations was investigated in the laboratory through the use of high pressure static experiments. Five different basalt samples were immersed in water equilibrated with supercritical CO2 containing 1wt% sulfur dioxide (SO2) and 1wt% oxygen (O2) at reservoir conditions (~100 bar, 90°C) for 49 and 98 days. Gypsum (CaSO4) was a common precipitate, occurred early as elongated blades with striations, and served as substrates for other mineral products. Bimodal pulses of water released during dehydroxylation were key indicators along with X-ray diffraction for verifying the presences of jarosite-alunite group minerals. Well-developed pseudocubic jarosite crystals formed surface coatings, and in some instances mixtures of natrojarosite and natroalunite aggregated into spherically shaped structures measuring 100 ?m in diameter. Reaction products were also characterized using infrared spectroscopy, which indicated OH and Fe-O stretching modes. The presences of jarosite-alunite group minerals were found in the lower wavenumber region from 700–400 cm-1. A strong preferential incorporation of Fe(III) into natrojarosite was attributed to the oxidation potential of O2. Evidence of CO2 was detected during thermal decomposition of precipitates, suggesting the onset of mineral carbonation.

  7. Effect of SiO2 coating in bolometric Ge light detectors for rare event searches

    E-Print Network [OSTI]

    J. W. Beeman; A. Gentils; A. Giuliani; M. Mancuso; G. Pessina; O. Plantevin; C. Rusconi

    2012-12-01

    In germanium-based light detectors for scintillating bolometers, a SiO$_2$ anti-reflective coating is often applied on the side of the germanium wafer exposed to light with the aim to improve its light collection efficiency. In this paper, we report about a measurement, performed in the temperature range 25-35 mK, of the light-collection increase obtained thanks to this method, which resulted to be of the order of 20%. The procedure followed has been carefully selected in order to minimize systematic effects. The employed light sources have the same spectral features (peaking at $\\sim 630$ nm wavelength) that will characterise future neutrinoless double beta decay experiments on the isotope $^{82}$Se and based on ZnSe crystals, such as LUCIFER. The coupling between source and light detector reproduces the configuration used in scintillating bolometers. The present measurement clarifies the role of SiO$_2$ coating and describes a method and a set-up that can be extended to the study of other types of coatings and luminescent materials.

  8. A three-dimensional Macroporous Cu/SnO2 composite anode sheet prepared via a novel method

    SciTech Connect (OSTI)

    Xu, Wu; Canfield, Nathan L.; Wang, Deyu; Xiao, Jie; Nie, Zimin; Zhang, Jiguang

    2010-11-01

    Macroporous Cu/SnO2 composite anode sheets were prepared by a novel method which is based on slurry blending, tape casting, sintering, and reducing of metal oxides. Such composite Cu/SnO2 anode sheets have no conducting carbons and binders, and show improved discharge capacity and cycle life than the SnO2 electrode from conventional tape-casting method on Cu foil. This methodology produces limited wastes and is also adaptable to many other materials. It is easy for industrial scale production. With the optimization of particle size of the metal oxide, pore size, pore volume and other factors, this kind of macroporous Cu/SnO2 composite anode sheets could give significantly improved capacity and cycle life.

  9. Preferred Molecular Orientation of Coumarin 343 on TiO2 Surfaces: Application to Dye-Sensitized Solar Cells

    E-Print Network [OSTI]

    McCree-Grey, Jonathan; Cole, Jacqueline Manina; Evans, Peter

    2015-07-23

    The dye…TiO2 interfacial structure in working electrodes of dye-sensitized solar cells (DSCs) is known to influence its photovoltaic device performance. Despite this, direct and quantitative reports of such structure remain sparse. This case study...

  10. Vehicle Technologies Office Merit Review 2015: Efficient Rechargeable Li/O2 Batteries Utilizing Stable Inorganic Molten Salt Electrolytes

    Office of Energy Efficiency and Renewable Energy (EERE)

    Presentation given by Liox at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about efficient rechargeable Li/O2 batteries...

  11. Phonon-energy-coupling enhancement: Strengthening the chemical bonds of the SiO2/Si system

    E-Print Network [OSTI]

    Chen, Zhi

    Phonon-energy-coupling enhancement: Strengthening the chemical bonds of the SiO2/Si system Zhi Chena and Jun Guo Department of Electrical and Computer Engineering and Center for Nanoscale Science

  12. Tuning the oxide/organic interface: Benzene on SnO2,,101... Matthias Batzill,a)

    E-Print Network [OSTI]

    Diebold, Ulrike

    Tuning the oxide/organic interface: Benzene on SnO2,,101... Matthias Batzill,a) Khabibulakh Katsiev,16 As a model molecule for simulating an organic semiconductor film benzene was chosen as a simple -conjugated

  13. Propane reacts with O2 and H2 on gold supported TS-1 to form oxygenates with high selectivity

    E-Print Network [OSTI]

    Bravo Suarez, Juan J.

    2008-06-13

    Gold nanoparticles supported on a microporous titanosilicate (TS-1) were found to be highly selective (95%) towards the formation of acetone and isopropanol from propane, O2, and H2 at moderate temperatures (443 K)....

  14. Understanding the Nucleation and Growth of Metals on TiO2: Co Compared to Au, Ni, and Pt

    E-Print Network [OSTI]

    Henkelman, Graeme

    The Co-TiO2 system has also been used for other industrially relevant catalytic processes, including the steam reforming of ethanol,24 preferential oxidation of CO in hydrogen,25 and oxidative dehydrogenation

  15. Two-stage epitaxial growth of vertically-aligned SnO2 nano-rods on (001) ceria

    SciTech Connect (OSTI)

    Solovyov, VF; Wu, LJ; Rupich, MW; Sathyamurthy, S; Li, XP; Li, Q

    2014-12-15

    Growth of high-aspect ratio oriented tin oxide, SnO2, nano-rods is complicated by a limited choice of matching substrates. We show that a (001) cerium oxide, CeO2, surface uniquely enables epitaxial growth of tin-oxide nano-rods via a two-stage process. First, (100) oriented nano-wires coat the ceria surface by lateral growth, forming a uniaxially-textured SnO2 deposit. Second, vertical SnO2 nano-rods nucleate on the deposit by homoepitaxy. We demonstrate growth of vertically oriented 1-2 mu m long nano-rods with an average diameter of approximate to 20 nm. 2014 Elsevier B.V. All rights reserved.

  16. THE JOURNAL OF CHEMICAL PHYSICS 135, 104303 (2011) The visible spectrum of zirconium dioxide, ZrO2

    E-Print Network [OSTI]

    Maier, John Paul

    2011-01-01

    THE JOURNAL OF CHEMICAL PHYSICS 135, 104303 (2011) The visible spectrum of zirconium dioxide, ZrO2; published online 8 September 2011) The electronic spectrum of a cold molecular beam of zirconium dioxide, Zr

  17. Coexistence of different charge states in Ta-doped monoclinic HfO2: Theoretical and experimental approaches

    E-Print Network [OSTI]

    Svane, Axel Torstein

    and with the addition of small amounts of impurities, it has applications ranging from solid oxide fuel cell attention due to its potential technological applications. HfO2 is a wide-band- gap semiconductor

  18. Studies of NafionRuO2xH2O Composite Membranes Catherine Lepiller,a

    E-Print Network [OSTI]

    Hitchcock, Adam P.

    prepared by the recast method. The hydration level of RuO2·xH2O was varied by heat-dispersive X-ray analysis and scanning X-ray transmission microscopy that both show the presence of a thin layer 5 m of RuO2·xH2O on one side of the membrane. Scanning transmission X-ray microscopy also reveals

  19. Enhanced Visible Light Photocatalytic Activity for TiO2 Nanotube Array Films by Codoping with Tungsten and Nitrogen

    E-Print Network [OSTI]

    Zhang, Min; Lu, DanDan; Yang, Jianjun

    2013-01-01

    A series of W, N codoped TiO2 nanotube arrays with different dopant contents were fabricated by anodizing in association with hydrothermal treatment. The samples were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and ultraviolet-visible light diffuse reflection spectroscopy. Moreover, the photocatalytic activity of W and N codoped TiO2 nanotube arrays was evaluated by degradation of methylene blue under visible light irradiation.

  20. In Situ Time-Resolved Characterization of Ni-MoO2 Catalysts for the Water-Gas Shift Reaction

    SciTech Connect (OSTI)

    Wen,W.; Calderon, J.; Brito, J.; Marinkovic, N.; Hanson, J.; Rodriquez, J.

    2008-01-01

    Active catalysts for the water-gas shift (WGS, CO + H2O ? H2 + CO2) reaction were synthesized from nickel molybdates ({beta}-NiMoO4 and nH2O{center_dot}NiMoO4) as precursors, and their structural transformations were monitored using in situ time-resolved X-ray diffraction and X-ray absorption near-edge spectroscopy. In general, the nickel molybdates were not stable and underwent partial reduction in the presence of CO or CO/H2O mixtures at high temperatures. The interaction of {beta}-NiMoO4 with the WGS reactants at 500 C led to the formation of a mixture of Ni (24 nm particle size) and MoO2 (10 nm particle size). These Ni-MoO2 systems displayed good catalytic activity at 350, 400, and 500 C. At 350 and 400 C, catalytic tests revealed that the Ni-MoO2 system was much more active than isolated Ni (some activity) or isolated MoO2 (negligible activity). Thus, cooperative interactions between the admetal and oxide support were probably responsible for the high WGS activity of Ni-MoO2. In a second synthetic approach, the NiMoO4 hydrate was reduced to a mixture of metallic Ni, NiO, and amorphous molybdenum oxide by direct reaction with H2 gas at 350 C. In the first pass of the water-gas shift reaction, MoO2 appeared gradually at 500 C with a concurrent increase of the catalytic activity. For these catalysts, the particle size of Ni (4 nm) was much smaller than that of the MoO2 (13 nm). These systems were found to be much more active WGS catalysts than Cu-MoO2, which in turn is superior to commercial low-temperature Cu-ZnO catalysts.

  1. Detoxification of superoxide without production of H2O2: antioxidant activity of superoxide reductase complexed with ferrocyanide

    E-Print Network [OSTI]

    Molina-Heredia, Fernando P; Berthomieu, Catherine; Touati, Danièle; Tremey, Emilie; Favaudon, Vincent; Adam, Virgile; Nivière, Vincent

    2015-01-01

    The superoxide radical O(2)(-.) is a toxic by-product of oxygen metabolism. Two O(2)(-.) detoxifying enzymes have been described so far, superoxide dismutase and superoxide reductase (SOR), both forming H2O2 as a reaction product. Recently, the SOR active site, a ferrous iron in a [Fe(2+) (N-His)(4) (S-Cys)] pentacoordination, was shown to have the ability to form a complex with the organometallic compound ferrocyanide. Here, we have investigated in detail the reactivity of the SOR-ferrocyanide complex with O(2)(-.) by pulse and gamma-ray radiolysis, infrared, and UV-visible spectroscopies. The complex reacts very efficiently with O(2)(-.). However, the presence of the ferrocyanide adduct markedly modifies the reaction mechanism of SOR, with the formation of transient intermediates different from those observed for SOR alone. A one-electron redox chemistry appears to be carried out by the ferrocyanide moiety of the complex, whereas the SOR iron site remains in the reduced state. Surprisingly, the toxic H2O2 s...

  2. Ammonia formation from NO reaction with surface hydroxyls on rutile TiO2 (110) - 1×1

    SciTech Connect (OSTI)

    Kim, Boseong; Kay, Bruce D.; Dohnalek, Zdenek; Kim, Yu Kwon

    2015-01-15

    The reaction of NO with hydroxylated rutile TiO2(110)-1×1 surface (h-TiO2) was investigated as a function of NO coverage using temperature-programmed desorption. Our results show that NO reaction with h-TiO2 leads to formation of NH3 which is observed to desorb at ~ 400 K. Interestingly, the amount of NH3 produced depends nonlinearly on the coverage of NO. The yield increases up to a saturation value of ~1.3×1013 NH3/cm2 at a NO dose of 5×1013 NO/cm2, but subsequently decreases at higher NO doses. Preadsorbed H2O is found to have a negligible effect on the NH3 desorption yield. Additionally, no NH3 is formed in the absence of surface hydroxyls (HOb’s) upon coadsorption of NO and H2O on a stoichiometric TiO2(110) (s-TiO2(110)). Based on these observations, we conclude that nitrogen from NO has a strong preference to react with HOb’s on the bridge-bonded oxygen rows (but not with H2O) to form NH3. The absolute NH3 yield is limited by competing reactions of HOb species with titanium-bound oxygen adatoms to form H2O. Our results provide new mechanistic insight about the interactions of NO with hydroxyl groups on TiO2(110) .

  3. Striving toward noble-metal-free photocatalytic water splitting: The hydrogenated-graphene-TiO2 prototype

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Nguyen-Phan, Thuy -Duong; Luo, Si; Liu, Zongyuan; Gamalski, Andrew D.; Tao, Jing; Xu, Wenqian; Stach, Eric A.; Polyansky, Dmitry E.; Senanayake, Sanjaya D.; Fujita, Etsuko; et al

    2015-08-20

    Graphane, graphone and hydrogenated graphene (HG) have been extensively studied in recent years due to their interesting properties and potential use in commercial and industrial applications. The present study reports investigation of hydrogenated graphene/TiO2-x (HGT) nanocomposites as photocatalysts for H2 and O2 production from water without the assistance of a noble metal co-catalyst. By combination of several techniques, the morphologies, bulk/atomic structure and electronic properties of all the powders were exhaustively interrogated. Hydrogenation treatment efficiently reduces TiO2 nanoparticles, while the graphene oxide sheets undergo the topotactic transformation from a graphene-like structure to a mixture of graphitic and turbostratic carbon (amorphous/disordered)more »upon altering the calcination atmosphere from a mildly reducing to a H2-abundant environment. Remarkably, the hydrogenated graphene-TiO2-x composite that results upon H2-rich reduction exhibits the highest photocatalytic H2 evolution performance equivalent to low loading of Pt (~0.12 wt%), whereas the addition of HG suppresses the O2 production. As a result, we propose that such an enhancement can be attributed to a combination of factors including the introduction of oxygen vacancies and Ti3+ states, retarding the recombination of charge carriers and thus, facilitating the charge transfer from TiO2-x to the carbonaceous sheet.« less

  4. Electrochemically synthesized ordered TiO2 and platinum nanocomposite electrode: preparation, characterization, and application to photoelectrocatalytic methanol oxidation

    SciTech Connect (OSTI)

    Li, Zhizhou; Cui, Xiaoli; Lin, Yuehe

    2009-04-01

    In this work, the nanocomposite electrodes consisting of Pt and TiO2 nanotubular arrays have been synthesized, and the morphologies, structural, and photo-electrochemical properties of the electrodes are characterized by SEM, XRD, and electrochemical methods. Highly ordered TiO2 nanotubular arrays can be obtained through anodization of titanium. The platinum nanoparticles are electrodeposited into TiO2 nanotubes by a chronopotentiometry method. Cyclic voltammetry and XRD measurements can confirm the presence of platinum in this nanocomposite electrode. The nanostructural electrode greatly improved performances for methanol oxidation under UV-Vis illumination compared to that without illumination. An enhancement of 58% in the current density has been observed upon illumination with UV-Vis light irradiance at an intensity of 50 mW/cm2. The improved performance of the TiO2/Pt nanocomposite electrode results from a enhanced methanol oxidation by photo-generated holes in the TiO2 nanoarrays under illumination and a synergistic effectiveness between TiO2 and Pt nanoparticles.

  5. Specific heat and energy for the three-dimensional O(2) model

    E-Print Network [OSTI]

    S. Holtmann; J. Engels; T. Schulze

    2001-09-19

    We investigate the three-dimensional O(2) model on lattices of size 8^3 to 160^3 close to the critical point at zero magnetic field. We confirm explicitly the value of the critical coupling J_c found by Ballesteros et al. and estimate there the universal values of g_r and xi/L. At the critical point we study the finite size dependencies of the energy density epsilon and the specific heat C. We find that the nonsingular part of the specific heat C_{ns} is linearly dependent on 1/alpha. From the critical behaviour of the specific heat for T not T_c on the largest lattices we determine the universal amplitude ratio A+/A-. The alpha- dependence of this ratio is close to the phenomenological relation A+/A- = 1-4alpha.

  6. Nanoscale Laser-Induced Spallation in SiO2 Films Containing Gold Nanoparticles

    SciTech Connect (OSTI)

    Kudryashov, S.I.; Allen, S.D.; Papernov, S.; Schmid, A.W.

    2006-02-16

    A phenomenological theory of ultraviolet pulsed-laser-induced spallation is proposed to interpret crater formation in SiO2 thin films containing absorbing 18.5-nm gold particles. The theory considers a spherical thermoacoustic stress wave propagating from a thermal source produced by laser-energy absorption inside the particle and surrounding ionized volume. Calculations show that the tensile stress associated with such an acoustic wave may exceed the local strength of the material and cause fracture and spallation of the top film portion. The theory provides an explanation of the experimentally observed complex (two-cone) shape of craters formed in the film with particle-lodging depth exceeding 110 nm. Theoretical estimates for the threshold stress amplitude and peak temperature in the thermal source are in qualitative agreement with the experimental observations.

  7. Nucleation and Growth of Crystalline Grains in RF-Sputtered TiO2Films

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Johnson, J. C.; Ahrenkiel, S. P.; Dutta, P.; Bommisetty, V. R.

    2009-01-01

    AmorphousTiO2thin films were radio frequency sputtered onto siliconmonoxide and carbon support films on molybdenum transmission electron microscope (TEM) grids and observed during in situ annealing in a TEM heating stage at250?C. The evolution of crystallization is consistent with a classical model of homogeneous nucleation and isotropic grain growth. The two-dimensional grain morphology of the TEM foil allowed straightforward recognition of amorphous and crystallized regions of the films, for measurement of crystalline volume fraction and grain number density. By assuming that the kinetic parameters remain constant beyond the onset of crystallization, the final average grain size was computed, using an analyticalmore »extrapolation to the fully crystallized state. Electron diffraction reveals a predominance of the anatase crystallographic phase.« less

  8. Specific heat and energy for the three-dimensional O(2) model

    E-Print Network [OSTI]

    Holtmann, S; Schulze, T

    2002-01-01

    We investigate the three-dimensional O(2) model on lattices of size 8^3 to 160^3 close to the critical point at zero magnetic field. We confirm explicitly the value of the critical coupling J_c found by Ballesteros et al. and estimate there the universal values of g_r and xi/L. At the critical point we study the finite size dependencies of the energy density epsilon and the specific heat C. We find that the nonsingular part of the specific heat C_{ns} is linearly dependent on 1/alpha. From the critical behaviour of the specific heat for T not T_c on the largest lattices we determine the universal amplitude ratio A+/A-. The alpha- dependence of this ratio is close to the phenomenological relation A+/A- = 1-4alpha.

  9. Nucleation and Growth of Crystalline Grains in RF-Sputtered TiO 2 Films

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Johnson, J. C.; Ahrenkiel, S. P.; Dutta, P.; Bommisetty, V. R.

    2009-01-01

    Amorphous TiO 2 thin films were radio frequency sputtered onto siliconmonoxide and carbon support films on molybdenum transmission electron microscope (TEM) grids and observed during in situ annealing in a TEM heating stage at 250 ? C. The evolution of crystallization is consistent with a classical model of homogeneous nucleation and isotropic grain growth. The two-dimensional grain morphology of the TEM foil allowed straightforward recognition of amorphous and crystallized regions of the films, for measurement of crystalline volume fraction and grain number density.more »By assuming that the kinetic parameters remain constant beyond the onset of crystallization, the final average grain size was computed, using an analytical extrapolation to the fully crystallized state. Electron diffraction reveals a predominance of the anatase crystallographic phase. « less

  10. Monte Carlo simulation of O(2) phi^4 field theory in three dimensions

    E-Print Network [OSTI]

    Peter Arnold; Guy D. Moore

    2003-07-24

    Using standard numerical Monte Carlo lattice methods, we study non-universal properties of the phase transition of three-dimensional phi^4 theory of a 2-component real field phi = (phi_1,phi_2) with O(2) symmetry. Specifically, we extract the renormalized values of /u and r/u^2 at the phase transition, where the continuum action of the theory is \\int d^3x [ (1/2) |\\grad\\phi|^2 + \\half r \\phi^2 + {u\\over4!} \\phi^4 ]. These values have applications to calculating the phase transition temperature of dilute or weakly-interacting Bose gases (both relativistic and non-relativistic). In passing, we also provide perturbative calculations of various O(a) lattice-spacing errors in three-dimensional O(N) scalar field theory, where (a) is the lattice spacing.

  11. Describing excited state relaxation and localization in TiO2 nanoparticles using TD-DFT

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Berardo, Enrico; Hu, Han -Shi; van Dam, Hubertus J. J.; Shevlin, Stephen A.; Woodley, Scott M.; Kowalski, Karol; Zwijnenburg, Martijn A.

    2014-02-26

    We have investigated the description of excited state relaxation in naked and hydrated TiO2 nanoparticles using Time-Dependent Density Functional Theory (TD-DFT) with three common hybrid exchange-correlation (XC) potentials; B3LYP, CAM-B3LYP and BHLYP. Use of TD-CAM-B3LYP and TD-BHLYP yields qualitatively similar results for all structures, which are also consistent with predictions of coupled cluster theory for small particles. TD-B3LYP, in contrast, is found to make rather different predictions; including apparent conical intersections for certain particles that are not observed with TD-CAM-B3LYP nor with TD-BHLYP. In line with our previous observations for vertical excitations, the issue with TD-B3LYP appears to be themore »inherent tendency of TD-B3LYP, and other XC potentials with no or a low percentage of Hartree-Fock Like Exchange, to spuriously stabilize the energy of charge-transfer (CT) states. Even in the case of hydrated particles, for which vertical excitations are generally well described with all XC potentials, the use of TD-B3LYP appears to result in CT-problems for certain particles. We hypothesize that the spurious stabilization of CT-states by TD-B3LYP even may drive the excited state optimizations to different excited state geometries than those obtained using TD-CAM-B3LYP or TD-BHLYP. In conclusion, focusing on the TD-CAM-B3LYP and TD-BHLYP results, excited state relaxation in naked and hydrated TiO2 nanoparticles is predicted to be associated with a large Stokes’ shift.« less

  12. Growth and structure of water on SiO2 films on Si investigated by Kelvin probe microscopy and in situ X-ray Spectroscopies

    E-Print Network [OSTI]

    Verdaguer, A.; Weis, C.; Oncins, G.; Ketteler, G.; Bluhm, H.; Salmeron, M.

    2008-01-01

    Growth and Structure of water on SiO 2 films on Simbsalmeron@lbl.gov The growth of water on thin SiO 2 films75% relative humidity (RH) water adsorbs forming a uniform

  13. Measuring Metabolism Using O2 and CO2 Class note readings: Review the section on aerobic metabolism. Be sure that you understand

    E-Print Network [OSTI]

    Prestwich, Ken

    Principle of Respiratory Gas Measurements: When using gas fraction respirometry, V · O2 and V · CO21 Measuring Metabolism Using O2 and CO2 1 Class note readings: Review the section on aerobic of oxygen used per unit time or M · O2 which is the number of mols of oxygen used per unit time or · V · CO2

  14. Characteristics of SiO2 Film Grown by Atomic Layer Deposition as the Gate Insulator of Low-Temperature Polysilicon Thin-Film Transistors

    E-Print Network [OSTI]

    Cao, Guozhong

    Characteristics of SiO2 Film Grown by Atomic Layer Deposition as the Gate Insulator of Low a Corresponding author: skrha@hanbat.ac.kr Keywords: atomic layer deposition (ALD), silicon dioxide (SiO2), dichlorosilane (SiH2Cl2), ozone (O3) Abstract. SiO2 films were prepared by atomic layer deposition (ALD

  15. Growth of Aligned Single-Crystalline Rutile TiO2 Nanowires on Arbitrary Substrates and Their Application in Dye-Sensitized Solar Cells

    E-Print Network [OSTI]

    Zhou, Chongwu

    the anodization method has been used to grow TiO2 nanotubes,28 an oblique angle deposition method has beenGrowth of Aligned Single-Crystalline Rutile TiO2 Nanowires on Arbitrary Substrates TiO2 is a wide band gap semiconductor with important applications in photovoltaic cells

  16. A novel magnetically separable TiO2/CoFe2O4 nanofiber with high photocatalytic activity under UVvis light

    E-Print Network [OSTI]

    Gong, Jian Ru

    photocatalytic ability, various morphologies of TiO2 including nanoparticles, nanotubes, nanostructured filmsA novel magnetically separable TiO2/CoFe2O4 nanofiber with high photocatalytic activity under UV pollutants [1,2]. Titanium dioxide (TiO2) is considered as an interesting material and has been widely

  17. Low-Cost High-Performance Solid-State Asymmetric Supercapacitors Based on MnO2 Nanowires and Fe2O3 Nanotubes

    E-Print Network [OSTI]

    Wang, Zhong L.

    performance. For example, Lu et al. developed a solid-state flexible ASC device with hydrogenated TiO2@MnO2 core-shell nanowires (NWs) as the positive electrode and hydro- genated TiO2@C core-shell NWs Nanotubes Peihua Yang, Yong Ding, Ziyin Lin, Zhongwei Chen, Yuzhi Li, Pengfei Qiang, Masood Ebrahimi, Wenjie

  18. Gas Transport and Exchange: Interaction Between O2 and CO2 CJ Brauner and JL Rummer, University of British Columbia, Vancouver, BC, Canada

    E-Print Network [OSTI]

    Wood, Spencer

    Gas Transport and Exchange: Interaction Between O2 and CO2 Exchange CJ Brauner and JL Rummer Nonlinear Bohr­Haldane Effect within the OEC Basis for the Interaction between O2 and CO2: Implications of Non-Steady-State Conditions for the Bohr­Haldane Effect Interaction between O2 and CO2 Exchange

  19. Efficiency of clay-TiO2 nanocomposites on the photocatalytic eliminationof a model hydrophobic air pollutant

    SciTech Connect (OSTI)

    Kibanova, Daria; Cervini-Silva, Javiera; Destaillats, Hugo

    2009-01-01

    Clay-supported TiO2 photocatalysts can potentially improve the performance of air treatment technologies via enhanced adsorption and reactivity of target volatile organic compounds (VOCs). In this study, a bench-top photocatalytic flow reactor was used to evaluate the efficiency of hectorite-TiO2 and kaolinite-TiO2, two novel composite materials synthesized in our laboratory. Toluene, a model hydrophobic VOC and a common indoor air pollutant, was introduced in the air stream at realistic concentrations, and reacted under UVA (gamma max = 365 nm) or UVC (gamma max = 254 nm) irradiation. The UVC lamp generated secondary emission at 185 nm, leading to the formation of ozone and other short-lived reactive species. Performance of clay-TiO2 composites was compared with that of pure TiO2 (Degussa P25), and with UV irradiation in the absence of photocatalyst under identical conditions. Films of clay-TiO2 composites and of P25 were prepared by a dip-coating method on the surface of Raschig rings, which were placed inside the flow reactor. An upstream toluene concentration of ~;;170 ppbv was generated by diluting a constant flow of toluene vapor from a diffusion source with dry air, or with humid air at 10, 33 and 66percent relative humidity (RH). Toluene concentrations were determined by collecting Tenax-TA (R) sorbent tubes downstream of the reactor, with subsequent thermal desorption -- GC/MS analysis. The fraction of toluene removed, percentR, and the reaction rate, Tr, were calculated for each experimental condition from the concentration changes measured with and without UV irradiation. Use of UVC light (UV/TiO2/O3) led to overall higher reactivity, which can be partially attributed to the contribution of gas phase reactions by short-lived radical species. When the reaction rate was normalized to the light irradiance, Tr/I gamma, the UV/TiO2 reaction under UVA irradiation was more efficient for samples with a higher content of TiO2 (P25 and Hecto-TiO2), but not for Kao-TiO2. In all cases, reaction rates peaked at 10percent RH, with Tr values between 10 and 50percent higher than those measured under dry air. However, a net inhibition was observed as RH increased to 33percent and 66percent, indicating that water molecules competed effectively with toluene for reactive surface sites and limited the overall photocatalytic conversion. Compared to P25, inhibition by co-adsorbed water was less significant for Kao-TiO2 samples, but was more dramatic for Hecto-TiO2 due to the high water uptake capacity of hectorite.

  20. Structure of epitaxial (Fe,N) codoped rutile TiO2 thin films by x-ray absorption

    SciTech Connect (OSTI)

    Kaspar, Tiffany C.; Ney, A.; Mangham, Andrew N.; Heald, Steve M.; Joly, Yves; Ney, V.; Wilhelm, F.; Rogalev, A.; Yakou, Flora; Chambers, Scott A.

    2012-07-23

    Homoepitaxial thin films of Fe:TiO2 and (Fe,N):TiO2 were deposited on rutile(110) by molecular beam epitaxy. X-ray absorption near edge spectroscopy (XANES) spectra were collected at the Ti L-edge, Fe L-edge, O K-edge, N K-edge, and Ti K-edge. No evidence of structural disorder associated with a high concentration of oxygen vacancies is observed. Substitution of Fe for Ti could not be confirmed, although secondary phase Fe2O3 and metallic Fe can be ruled out. The similarity of the N K-edge spectra to O, and the presence of a strong x-ray linear dichroism (XLD) signal for the N K-edge, indicates that N is substitutional for O in the rutile lattice, and is not present as a secondary phase such as TiN. Simulations of the XANES spectra qualitatively confirm substitution, although N appears to be present in more than one local environment. Neither Fe:TiO2 nor (Fe,N):TiO2 exhibit intrinsic room temperature ferromagnetism, despite the presence of mixed valence Fe(II)/Fe(III) in the reduced (Fe,N):TiO2 film.

  1. Effect of Sodium on the Catalytic Properties of VOx/CeO2 Catalysts for Oxidative Dehydrogenation of Methanol

    SciTech Connect (OSTI)

    Li, Yan; Wei, Zhehao; Sun, Junming; Gao, Feng; Peden, Charles HF; Wang, Yong

    2013-03-21

    A series of VOx/CeO2 catalysts with various sodium loadings (Na/V ratio from 0 to 1) has been studied for oxidative dehydrogenation (ODH) of methanol. The effect of sodium on the surface structure, redox properties, and surface acidity/basicity of VOx/CeO2 was investigated using hydrogen temperature-programmed reduction (H2-TPR), Raman spectroscopy, and Diffuse Reflectance Infrared Fourier Transform spectroscopy (DRIFT). The experimental results indicate that the effect of sodium on VOx/CeO2 is highly dependent on the Na/V ratio. At a low Na/V ratio (Na/V<0.25), sodium addition only slightly decreases the redox properties of VOx/CeO2 and has little effect on its activity and selectivity to formaldehyde, even though the Brönsted acidity is almost completely eliminated at a Na/V ratio of 0.25. At a high Na/V ratio (Na/V>0.25), sodium addition greatly alters the nature of the active sites by V-O-Ce bond cleavage and V-O-Na bond formation, leading to significantly reduced activity of the VOx/CeO2 catalysts. At Na/V>0.25, the selectivity to formaldehyde also decreases with increasing Na/V ratio due to: (1) the suppressed reducibility of VOx, and (2) increased basicity leading to increased CO2.

  2. Semantic Historian for IoT Applications

    Broader source: Energy.gov (indexed) [DOE]

    and maintained by SmartCloud - Applications hosted either at customer premise, in cloud, or at secured data center * Investment from Rockwell Automation in 2013 3 > Customers...

  3. Standards for the wireless IoT

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LIST OF APPLICABLE DIRECTIVESDepartmentSpecialCode of Record Standard ReviewFactZigBee

  4. Enhancing electrochemical intermediate solvation through electrolyte anion selection to increase nonaqueous Li-O$_2$ battery capacity

    E-Print Network [OSTI]

    Burke, Colin M; Khetan, Abhishek; Viswanathan, Venkatasubramanian; McCloskey, Bryan D

    2015-01-01

    Among the 'beyond Li-ion' battery chemistries, nonaqueous Li-O$_2$ batteries have the highest theoretical specific energy and as a result have attracted significant research attention over the past decade. A critical scientific challenge facing nonaqueous Li-O$_2$ batteries is the electronically insulating nature of the primary discharge product, lithium peroxide, which passivates the battery cathode as it is formed, leading to low ultimate cell capacities. Recently, strategies to enhance solubility to circumvent this issue have been reported, but rely upon electrolyte formulations that further decrease the overall electrochemical stability of the system, thereby deleteriously affecting battery rechargeability. In this study, we report that a significant enhancement (greater than four-fold) in Li-O$_2$ cell capacity is possible by appropriately selecting the salt anion in the electrolyte solution. Using $^7$Li nuclear magnetic resonance and modeling, we confirm that this improvement is a result of enhanced Li...

  5. Imaging Hindered Rotations of Alkoxy Species on TiO2(110)

    SciTech Connect (OSTI)

    Zhang, Zhenrong; Rousseau, Roger J.; Gong, Jinlong; Kay, Bruce D.; Dohnalek, Zdenek

    2009-12-16

    We present the first study of the rotational dynamics of organic species on any oxide surface. Specifically, variable-temperature scanning tunneling microscopy (STM) and dispersion-corrected density functional theory are used to study the alkyl chain conformational disorder and dynamics of 1-, 2-, 3- and 4-octoxy on rutile TiO2(110). Initially, the geminate pairs of the octoxy and bridging hydroxyl species are created via octanol dissociation on bridging-oxygen (Ob) vacancy defects. The STM images provide time averaged snapshots of octoxy species rotating among multiple energetically nearly-degenerate configurations accessible at a given temperature. In the calculations we find that the underlying corrugated potential energy surface is a result of the interplay between attractive Van der Waals dispersion forces leading to weak attractive C...Ti and repulsive C...Ob interactions which lead to large barriers of 50-70kJmol-1 for the rotation of the octoxy alkyl chains across the Ob rows. In the presence of the germinal hydroxyl groups we find that the relative populations of the various conformations as well as the rotational barriers are perturbed by the presence of geminate hydroxyl due to additional C...hydroxyl repulsions.

  6. Level Alignment of a Prototypical Photocatalytic System: Methanol on TiO2(110)

    SciTech Connect (OSTI)

    Migani, Annapaola; Mowbray, Duncan J.; Iacomino, Amilcare; Zhao, Jin; Petek, Hrvoje

    2013-08-07

    Photocatalytic activity depends on the optimal alignment of electronic levels at the molecule? semiconductor interface. Establishing the level alignment experimentally is complicated by the uncertain chemical identity of the surface species. We address the assignment of the occupied and empty electronic levels for the prototypical photocatalytic system consisting of methanol on a rutile TiO2(110) surface. Using many-body quasiparticle (QP) techniques, we show that the frontier levels measured in UV photoelectron and two-photon photoemission spectroscopy experiments can be assigned to molecularly chemisorbed methanol rather than its dissociated product, the methoxy species. We find that the highest occupied molecular orbital of the methoxy species is much closer to the valence band maximum, suggesting why it is more photocatalytically active than the methanol molecule. We develop a general semiquantitative model for predicting many-body QP energies based on the electronic screening within the bulk, molecular, or vacuum regions of the wave functions at molecule?semiconductor interfaces.

  7. Ternary Pt/Rh/SnO2 Electrocatalysts for Oxidizing Ethanol to CO2

    SciTech Connect (OSTI)

    Kowal, A.; Li, M; Shao, M; Sasaki, K; Vukmirovic, M; Zhang, J; Marinkovic, N; Liu, P; Frenkel, A; Adzic, R

    2009-01-01

    Ethanol, with its high energy density, likely production from renewable sources and ease of storage and transportation, is almost the ideal combustible for fuel cells wherein its chemical energy can be converted directly into electrical energy. However, commercialization of direct ethanol fuel cells has been impeded by ethanol's slow, inefficient oxidation even at the best electrocatalysts1, 2. We synthesized a ternary PtRhSnO2/C electrocatalyst by depositing platinum and rhodium atoms on carbon-supported tin dioxide nanoparticles that is capable of oxidizing ethanol with high efficiency and holds great promise for resolving the impediments to developing practical direct ethanol fuel cells. This electrocatalyst effectively splits the C-C bond in ethanol at room temperature in acid solutions, facilitating its oxidation at low potentials to CO2, which has not been achieved with existing catalysts. Our experiments and density functional theory calculations indicate that the electrocatalyst's activity is due to the specific property of each of its constituents, induced by their interactions. These findings help explain the high activity of Pt-Ru for methanol oxidation and the lack of it for ethanol oxidation, and point to the way to accomplishing the C-C bond splitting in other catalytic processes.

  8. Surface-structure sensitivity of CeO2 nanocrystals in photocatalysis and enhancing the reactivity with nanogold

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lei, Wanying; Zhang, Tingting; Gu, Lin; Liu, Ping; Rodriguez, José A.; Liu, Gang; Liu, Minghua

    2015-06-19

    Structure–function correlations are a central theme in heterogeneous (photo)catalysis. In this research, using aberration-corrected scanning transmission electron microscopy (STEM), the atomic surface structures of well-defined one-dimensional (1D) CeO2 nanorods (NRs) and 3D nanocubes (NCs) are directly visualized at subangstrom resolution. CeO2 NCs predominantly expose the {100} facet, with {110} and {111} as minor cutoff facets at the respective edges and corners. Notably, the outermost surface layer of the {100} facet is nearly O-terminated. Neither surface relaxations nor reconstructions on {100} are observed, indicating unusual polarity compensation, which is primarily mediated by near-surface oxygen vacancies. The surface of CeO2 NRs ismore »highly stepped, with the enclosed {110} facet exposing Ce cations and O anions on terraces. On the basis of STEM profile-view imaging and electronic structure analysis, the photoreactivity of CeO2 nanocrystals toward aqueous methyl orange degradation under UV is revealed to be surface-structure-sensitive, following the order: {110} >> {100}. The underlying surface-structure sensitivity can be attributed to the variation in low-coordinate surface cerium cations between {110} and {100} facets. To further enhance light absorption, Au nanoparticles (NPs) are deposited on CeO2 NRs to form Au/CeO2 plasmonic nanocomposites, which dramatically promotes the photoreactivity that is Au particle size- and excitation light wavelength-dependent. The mechanisms responsible for the enhancement of photocatalytic activity are discussed, highlighting the crucial role of photoexcited charge carrier transfer.« less

  9. Influence of particle size and water coverage on the thermodynamic properties of water confined on the surface of SnO2 cassiterite nanoparticles

    SciTech Connect (OSTI)

    Spencer, Elinor; Ross, Dr. Nancy; Parker, Stewart F.; Kolesnikov, Alexander I; Woodfield, Brian; Woodfield, K; Rytting, M; Boerio-Goates, Juliana; Navrotsky, Alexandra

    2011-01-01

    Inelastic neutron scattering (INS) data for SnO2 nanoparticles of three different sizes and varying hydration levels are presented. Data were recorded on five nanoparticle samples that had the following compositions: 2 nm SnO2*0.82H2O, 6 nm SnO2*0.055H2O, 6 nm SnO2*0.095H2O, 20 nm SnO2*0.072H2O, and 20 nm SnO2*0.092H2O. The isochoric heat capacity and vibrational entropy values at 298 K for the water confined on the surface of these nanoparticles were calculated from the vibrational density of states that were extracted from the INS data. This study has shown that the hydration level of the SnO2 nanoparticles influences the thermodynamic properties of the water layers and, most importantly, that there appears to be a critical size limit for SnO2 between 2 and 6 nm below which the particle size also affects these properties and above which it does not. These results have been compared with those for isostructural rutile-TiO2 nanoparticles [TiO2*0.22H2O and TiO2*0.37H2O], which indicated that water on the surface of TiO2 nanoparticles is more tightly bound and experiences a greater degree of restricted motion with respect to water on the surface of SnO2 nanoparticles. This is believed to be a consequence of the difference in chemical composition, and hence surface properties, of these metal oxide nanoparticles.

  10. 182 IEEE TRANSACTIONS ON NANOTECHNOLOGY, VOL. 12, NO. 2, MARCH 2013 Monitoring the Environmental Impact of TiO2

    E-Print Network [OSTI]

    Parker, Lynne E.

    the potential environmental impact of these nanoparticles. The goal of this research was to de- velop a plant-based sensor network for characterizing, monitoring, and understanding the environmental impact of TiO2 impact of nanomaterials. Index Terms--Biosystems, environmental monitoring, nanobio- science

  11. Kinetics-controlled growth of aligned mesocrystalline SnO2 nanorod arrays for lithium-ion batteries with

    E-Print Network [OSTI]

    Qi, Limin

    Kinetics-controlled growth of aligned mesocrystalline SnO2 nanorod arrays for lithium-ion batteries structures, lithium-ion batteries ABSTRACT A general method for facile kinetics-controlled growth of aligned material for lithium-ion batteries. 1 Introduction Lithium-ion batteries (LIBs) have been considered

  12. Growth of single-crystalline rutile TiO2 nanorods on fluorine-doped tin oxide glass for organicinorganic

    E-Print Network [OSTI]

    Cao, Guozhong

    ]. However, the full potential of the organic­ inorganic hybrid solar cells has been suppressed so far­inorganic hybrid solar cells Junting Xi · Orawan Wiranwetchayan · Qifeng Zhang · Zhiqiang Liang · Yueming Sun controlled by growth conditions. When used in hybrid solar cells, TiO2 NRs function as the continuous pathway

  13. Abiotic O$_{2}$ Levels on Planets around F, G, K, and M Stars: Possible False Positives for Life?

    E-Print Network [OSTI]

    Harman, C E; Schottelkotte, J C; Kasting, J F

    2015-01-01

    In the search for life on Earth-like planets around other stars, the first (and likely only) information will come from the spectroscopic characterization of the planet's atmosphere. Of the countless number of chemical species terrestrial life produces, only a few have the distinct spectral features and the necessary atmospheric abundance to be detectable. The easiest of these species to observe in Earth's atmosphere is O$_{2}$ (and its photochemical byproduct, O$_{3}$). But O$_{2}$ can also be produced abiotically by photolysis of CO$_{2}$, followed by recombination of O atoms with each other. CO is produced in stoichiometric proportions. Whether O$_{2}$ and CO can accumulate to appreciable concentrations depends on the ratio of far-UV to near-UV radiation coming from the planet's parent star and on what happens to these gases when they dissolve in a planet's oceans. Using a one-dimensional photochemical model, we demonstrate that O$_{2}$ derived from CO$_{2}$ photolysis should not accumulate to measurable c...

  14. Reactivity Screening of Anatase TiO2 Nanotube Arrays and Anatase Thin Films: A Surface Chemistry Point of View

    SciTech Connect (OSTI)

    Funk, S.; Hokkanen, B.; Nurkic, T.; Goering, J.; Kadossov, E.; Burghaus, Uwe; Ghicov, A.; Schmuki, P.; Yu, Zhongqing; Thevuthasan, Suntharampillai; Saraf, Laxmikant V.

    2008-09-19

    As a reactivity screening we collected thermal desorption spectroscopy (TDS) data of iso-butane, O2, CO2, and CO adsorbed on ordered TiO2 nanotube (TiNTs) arrays. As a reference system iso-butane adsorption on an anatase TiO2 thin film has been considered as well. The as-grown TiNTs are vertically aligned and amorphous. Polycrystalline (poly.) anatase or poly. anatase/rutile mixed nanotubes are formed by annealing confirmed by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The anatase thin film was grown on SrTiO3(001) and characterized by XRD and atomic force microscopy (AFM). Surprisingly, oxygen distinctly interacts with the TiNTs whereas this process is not observed on fully oxidized single crystal rutile TiO2(110). Desorption temperatures of 110-150 K and 100-120 K were observed for CO2 and CO, respectively, on the TiNTs. Variations in the binding energies of the alkanes on TiNTs and anatase thin films also were present, i.e., a structure-activity relationship (SAR) is evident.

  15. Anatase TiO2 nanobelts with plasmonic Au decoration exhibiting efficient charge separation and enhanced activity

    E-Print Network [OSTI]

    Liu, Fuqiang

    and enhanced activity Chiajen Hsu, Yi Shen, Zi Wei, Dong Liu, Fuqiang Liu Department of Materials Science-light-active TiO2 has attracted lots of attention since 98% of the solar energy resides within the visible light energy states in the band gap to allow optical absorption of visible light. For example, both N

  16. Oxidative dehydrogenation (ODH) of ethane with O2 as oxidant on selected transition metal-loaded zeolites

    E-Print Network [OSTI]

    Poeppelmeier, Kenneth R.

    Oxidative dehydrogenation (ODH) of ethane with O2 as oxidant on selected transition metal Accepted 14 April 2009 Available online 17 May 2009 Keywords: Oxidative dehydrogenation Ethane Ethylene of ethane (ODHE) to ethylene were characterized. Acidic Ni-loaded Y zeolite exhibits an ethylene

  17. Intact Size-Selected Aun Clusters on a TiO2(110)-(1 1) Surface at Room Temperature

    E-Print Network [OSTI]

    Buratto, Steve

    ) images of evaporated Au and Ag, assumed to be monomeric in the vapor phase, that these metals sinter upon illuminated with a pulsed YAG laser beam (532 nm, 500 mJ/pulse max power), producing a gold plasma. Positive to cluster deposition, the clean TiO2(110)- (1 × 1) surface was prepared by multiple cycles of Ar+ ion

  18. Investigation of Local Environments in Nafion-SiO2 Composite Membranes used in Vanadium Redox Flow Batteries

    SciTech Connect (OSTI)

    Vijayakumar, M.; Schwenzer, Birgit; Kim, Soowhan; Yang, Zhenguo; Thevuthasan, Suntharampillai; Liu, Jun; Graff, Gordon L.; Hu, Jian Z.

    2012-04-01

    The proton conducting polymer composite membranes are of technological interest in many energy devices such as fuel cells and redox flow batteries. In particular, the polymer composite membranes such as SiO2 incorporated Nafion membranes are recently reported as highly promising for the redox flow batteries. However, there is conflicting reports regarding the performance of this Nafion-SiO2 composite membrane in the redox flow cell. This paper presents results of the analysis of the Nafion-SiO2 composite membrane used in a vanadium redox flow battery by nuclear magnetic resonance (NMR) spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier Transformed Infra Red (FTIR) spectroscopy, and ultraviolet visible spectroscopy. The XPS study reveals the chemical identity and environment of vanadium cations accumulated at the surface. On the other hand, the 19F and 29Si NMR measurement explores the nature of the interaction between the silica particles, Nafion side chains and diffused vanadium cations. The 29Si NMR shows that the silica particles interaction via hydrogen bonds to the sulfonic groups of Nafion and diffused vanadium cations. Based on these spectroscopic studies, the chemical environment of the silica particles inside the Nafion membrane and their interaction with diffusing vanadium cations during flow cell operations are discussed. This study discusses the origin of performance degradation of the Nafion-SiO2 composite membrane materials in vanadium redox flow batteries.

  19. JOURNAL OF MATERIALS SCIENCE LETTERS 17 (1998) 20832086 Effect of oxygen plasma treatment on SiO2 aerogel lms

    E-Print Network [OSTI]

    Jo, Moon-Ho

    1998-01-01

    aerogel ®lms H.-H. PARK, M.-H. JO, H.-R. KIM, S.-H. HYUN Department of Ceramic Engineering, Yonsei with a lower dielectric constant material as an intermetal dielectric (IMD). SiO2 aerogel is a promising aerogel ®lm with 70% porosity exhibited the static dielectric constant of 2 at 1 MHz, and a leakage

  20. Supporting information Evolution of Hollow TiO2 Nanostructures via the Kirkendall Effect Driven by Cation

    E-Print Network [OSTI]

    Wang, Xudong

    valve open). The chamber was cooled down naturally under N2 flow after growth. To acquire different 5 cm away from the precursor inlet nozzle. N2 gas with a flow rate of 40 sccm was introduced into the chamber to serve as the carrier gas. The system's base pressure was kept at 3.2 Torr. The hollow TiO2

  1. Voltage Oscillations in Single-Chamber Fuel Cells operating under a C3H8 / O2 mixture.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Voltage Oscillations in Single-Chamber Fuel Cells operating under a C3H8 / O2 mixture. Geoffroy : Jean-Paul Viricelle, viricelle@emse.fr Phone : 33 4 77 42 02 52 Abstract : Single-Chamber Fuel Cells this behaviour. Keywords: Single Chamber Fuel Cell, Propane, Oscillation, Anode. 1. Introduction Solid Oxide Fuel

  2. Constructing Hierarchical Interfaces: TiO2-Supported PtFe-FeOx Nanowires for Room Temperature CO Oxidation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhu, Huiyuan; Wu, Zili; Dong, Su; Veith, Gabriel M; Lu, Hanfeng; Zhang, Pengfei; Chai, Songhai; Dai, Sheng

    2015-08-05

    This is a report of a facile approach to constructing catalytic active hierarchical interfaces in one-dimensional (1D) nanostructure, exemplified by the synthesis of TiO2-supported PtFe–FeOx nanowires (NWs). The hierarchical interface, constituting atomic level interactions between PtFe and FeOx within each NW and the interactions between NWs and support (TiO2), enables CO oxidation with 100% conversion at room temperature. We identify the role of the two interfaces by probing the CO oxidation reaction with isotopic labeling experiments. Both the oxygen atoms (Os) in FeOx and TiO2 participate in the initial CO oxidation, facilitating the reaction through a redox pathway. Moreover, themore »intact 1D structure leads to the high stability of the catalyst. After 30 h in the reaction stream, the PtFe–FeOx/TiO2 catalyst exhibits no activity decay. These results provide a general approach and new insights into the construction of hierarchical interfaces for advanced catalysis.« less

  3. Journal of Power Sources 165 (2007) 509516 Direct NaBH4/H2O2 fuel cells

    E-Print Network [OSTI]

    Carroll, David L.

    2007-01-01

    Journal of Power Sources 165 (2007) 509­516 Direct NaBH4/H2O2 fuel cells George H. Mileya,e,, Nie online 5 December 2006 Abstract A fuel cell (FC) using liquid fuel and oxidizer is under investigation. H Published by Elsevier B.V. Keywords: Fuel cell; Hydrogen peroxide; Regenerative fuel cell; Sodium

  4. Olivine LiCoPO4 phase grown LiCoO2 cathode material for high density Li batteries

    E-Print Network [OSTI]

    Cho, Jaephil

    Olivine LiCoPO4 phase grown LiCoO2 cathode material for high density Li batteries Hyunjung Lee an increase in the cut-off voltage of the cell from 4.2 V to 4.4 V (vs. graphite). As an alterna- tive, we can

  5. Oxygen and CO Adsorption on Au/SiO2 Catalysts Prepared by Magnetron Sputtering: The Role of Gold Subsurface

    SciTech Connect (OSTI)

    Zheng, Xiaolin [Washington University, St. Louis; Veith, Gabriel M [ORNL; Redekop, Evgeniy [Washington University, St. Louis; Lo, Cynthia [Washington University, St. Louis; Yablonsky, Gregory [Washington University, St. Louis; Madix, Robert J [Harvard University; Friend, Cynthia [Harvard University; Gleaves, John t [Washington University, St. Louis

    2010-01-01

    Temporal Analysis of Products (TAP) reactor system is used to investigate CO oxidation behavior on Au/SiO2 catalysts prepared via the physical vapor deposition method magnetron sputtering. Au/SiO2 catalysts are a valuable model system for studying the reactivity of Au nanoparticles, since the SiO2 support plays little role in the reaction. The adsorption of CO on the catalyst was studied under TAP vacuum conditions and at different temperatures. The heat of CO adsorption estimated from TAP results by moment analysis is -23.9 kJ/mol which is high compared to heat of CO adsorption reported by other TAP groups studying Au/TiO2 catalysts [29]. The reaction over the catalyst pretreated with oxygen under different pretreatment pressures (vacuum pressures to 33.66 psia) was studied under TAP vacuum conditions via CO titration. It was found that the amount of oxygen available on the surface for CO oxidation is proportional to the pretreatment pressure.

  6. Cycle-Life Characterization of Automotive Lithium-Ion Batteries with LiNiO2 Cathode

    E-Print Network [OSTI]

    Cycle-Life Characterization of Automotive Lithium-Ion Batteries with LiNiO2 Cathode Yancheng Zhang of lithium- ion batteries for electric vehicles EVs and hybrid EVs HEVs . Substantial research has been- face, which is critical to the cycle life and calendar life of lithium- ion batteries.1,2 Unfortunately

  7. Novel CeO2-based Screen-Printed Potentiometric Electrodes for pH monitoring S. Betelu1*

    E-Print Network [OSTI]

    Boyer, Edmond

    in Europe to isolate and store radioactive waste. In France, the Callovo-Oxfordian formation (COx) is a possible candidate for nuclear waste storage. This work investigates the applicability of CeO2-based oxides or are anticipated in the COx formation during its evolution as radioactive waste repository due mainly

  8. A calorimetric analysis of a polymer electrolyte fuel cell and the production of H2O2 at the cathode

    E-Print Network [OSTI]

    Kjelstrup, Signe

    31.08.2009 1 A calorimetric analysis of a polymer electrolyte fuel cell and the production of H2O2 fuel cell that is operated on hydrogen and oxygen at 50 °C and 1 bar. The cell had a SolviCore Catalyst 1. INTRODUCTION The energy that is dissipated as heat in fuel cells is interesting for several

  9. Role of hydrogen in Ge/HfO2/Al gate stacks subjected to negative bias temperature instability

    E-Print Network [OSTI]

    Misra, Durgamadhab "Durga"

    Role of hydrogen in Ge/HfO2/Al gate stacks subjected to negative bias temperature instability N 2007; published online 17 January 2008 This work investigates the role of hydrogen and nitrogen in a Ge. Virtually unchanged interface state density as a function of NBTI indicates no atomic hydrogen release from

  10. ICP Plasma Jet For Target Interaction Studies Of O-atoms In O2 And CO2 Supersonic Flows

    SciTech Connect (OSTI)

    Dilecce, G.; Ambrico, P.F.; De Benedictis, S. [Istituto di Metodologie Inorganiche e dei Plasmai, CNR-sez. Ter. Bari, c/o Dipartimento di Chimica, Universita di Bari- Via Orabona 4, 7126 Bari (Italy)

    2005-05-16

    An RF plasma jet using a planar inductive discharge in CO2 or in O2 gases has been used to produce a supersonic flow of O atoms suitable for gas-surface interaction experiments. The supersonic O atom stream is characterized by 2D space resolved TALIF.

  11. Electron Microscopy Observation of TiO2 Nanocrystal Evolution in High-Temperature Atomic Layer Deposition

    E-Print Network [OSTI]

    Wang, Xudong

    ABSTRACT: Understanding the evolution of amorphous and crystalline phases during atomic layer deposition nanorods via the principle of vapor-phase oriented attachment. KEYWORDS: TiO2, atomic layer deposition, Ostwald-Lussac law, oriented attachment Atomic layer deposition (ALD) is a unique thin film growth

  12. TiO2 nanotube arrays grown in ionic liquids: high-efficiency in photocatalysis and pore-widening

    SciTech Connect (OSTI)

    Li, Huaqing; Qu, Jun; Cui, Qingzhou; Xu, Hanbing; Luo, Huimin; Chi, Miaofang; Meisner, Roberta Ann; Wang, Wei; Dai, Sheng

    2011-01-01

    Debris-free, long, well-separated TiO2 nanotube arrays were obtained using an ionic liquid (IL) as electrolyte. The high conductivity of IL resulted in fast pore widening and few contaminants from electrolyte decomposition leading to high photocatalytic efficiency in water splitting.

  13. Laser fluorescence study of AIO formed in the reaction AI + O2: Product state distribution, dissociation energy, and radiative

    E-Print Network [OSTI]

    Laser fluorescence study of AIO formed in the reaction AI + O2: Product state distribution, dissociation energy, and radiative lifetime P. J. Dagdigian*, H. W. Cruset, and R. N. Zare Department distributions are found to differ significantly, with v = 0 having more rotational excitation than v = I

  14. SnO2 functionalized AlGaN/GaN high electron mobility transistor for hydrogen sensing applications

    E-Print Network [OSTI]

    Florida, University of

    for spacecraft and other long-term sensing applications. However, hydrogen is a dangerous gas for storage for monitoring leakage of hydrogen storage equipment and fuel tanks for spacecraft and hydrogen fuel cellSnO2 functionalized AlGaN/GaN high electron mobility transistor for hydrogen sensing applications

  15. Calcification capacity of porous pHEMATiO2 composite Chao Li Yu-Feng Zheng Xia Lou

    E-Print Network [OSTI]

    Zheng, Yufeng

    calcification of synthetic biomaterials for applications in orthopaedic and dental surgery. It has been polymers for applica- tions as orthopaedic and dental implants. In this study, novel titanium dioxide (TiO2 recognised that deposition of hydroxyapatite (HA) like CaP onto biomaterials surfaces can facilitate direct

  16. DISSOCIATIVE CHARGE EXCHANGE AND IONIZATION OF O2 BY FAST H+ ENERGETIC ION INTERACTIONS IN EUROPA'S OXYGEN

    E-Print Network [OSTI]

    Johnson, Robert E.

    ABSTRACT Measurements of electron capture and ionization of O2 molecules in collisions with H+ and O+ ions to Oþ 2 product formation are shown to be dominant for both the H+ and the O+ projectiles in the capture, and sulfur ions (Cooper et al. 2001; Paranicas et al. 2002). Collisions with these ions can lead

  17. Microwave-Assisted Synthesis of SnO2 Nanosheets Photoanodes for Dye-Sensitized Solar Cells

    E-Print Network [OSTI]

    Cao, Guozhong

    Microwave-Assisted Synthesis of SnO2 Nanosheets Photoanodes for Dye-Sensitized Solar Cells Yajie microwave-assisted hydrothermal growth and used as photoanodes for dye-sensitized solar cells (DSCs nanosheets as photoanodes from microwave-assisted synthesis exhibited much enhanced energy conversion

  18. High-Efficiency Photoelectrocatalytic Hydrogen Generation Enabled by Palladium Quantum Dots-Sensitized TiO2 Nanotube Arrays

    E-Print Network [OSTI]

    Lin, Zhiqun

    High-Efficiency Photoelectrocatalytic Hydrogen Generation Enabled by Palladium Quantum Dots of hydrogen as a potential fuel for renewable energy.1 Among the various catalysts, the noble metal palladium ABSTRACT: TiO2 nanotube arrays (TNTAs) sensitized by palladium quantum dots (Pd QDs) exhibit highly

  19. Multi-Timescale Investigation of Radiation Damage near TiO2 Rutile Grain Boundaries

    SciTech Connect (OSTI)

    Xian-Ming Bai; Blas P. Uberuaga

    2012-04-01

    Although grain boundaries (GBs) have been experimentally demonstrated to serve as sinks for absorbing radiation induced defects and improving the radiation tolerance of materials, the detailed atomistic interactions between defects and GBs leading to this enhanced tolerance are not well understood. In oxide ceramics the interactions are further complicated as defects can be charged and grain boundaries may exhibit space charge and charge dipole effects. Here, we use two atomistic modeling methods to examine the role of GBs in a model oxide system, rutile TiO2, in modifying defect production during irradiation events. The GB studied is a symmetric tilt GB with a rotation axis of [100] and a rotation angle of 15.25{sup o}. We use molecular dynamics to investigate defect production near the GB at both 300K and 1000 K and find that the damage production is sensitive to the initial distance of the primary knock-on atom (PKA) from the GB. We find three distinct regimes in which GBs have different effects on modifying defect production. Similar to GBs in metals, the GB absorbs more interstitials than vacancies at certain distances while this behavior of biased loading of interstitials diminishes at other distances. Further, we obtain the statistics of both interstitial and vacancy clusters 2 produced in collision cascades in terms of their compositions at two temperatures. We find that perfectly stoichiometric defect clusters (Schottky and anti-Schottky clusters) represent a small fraction of the total defect clusters produced. Moreover, a significant reduction in the number of interstitial clusters at 1000 K compared to 300 K is thought to be a consequence of enhanced migration of interstitials towards the GB. Finally the kinetic properties of certain defect clusters are investigated with temperature accelerated dynamics, without any priori assumptions of migration mechanisms. We find that small interstitial clusters become mobile at high temperatures while small vacancy clusters do not. Multiple migration pathways exist and are typically complex and non-intuitive. We use this kinetic information to explain experimental observations and predict their long-time migration behavior near GBs.

  20. Air stable Al2O3-coated Li2NiO2 cathode additive as a surplus current consumer in a Li-ion cell

    E-Print Network [OSTI]

    Cho, Jaephil

    increases to 2.75V (2.85V vs. graphite), its discharge capacity decreases to 120 mAh/g, which corresponds for the irreversible capacity of the Li-ion cell using LiCoO2 and natural graphite as cathode and anode materials the complete decomposition of the Li2NiO2. 1. Introduction Most Li secondary batteries use LiCoO2 as a cathode

  1. SiO2 aerogel film as a novel intermetal dielectric Moon-Ho Jo, Hyung-Ho Park,a)

    E-Print Network [OSTI]

    Jo, Moon-Ho

    SiO2 aerogel film as a novel intermetal dielectric Moon-Ho Jo, Hyung-Ho Park,a) Dong-Joon Kim, Sang, cross talk, and interconnection delay in the deep submicron device regime. SiO2 aerogel is one of the successful fabrication of a SiO2 aerogel film as well as its material properties and electrical properties

  2. The effects of zirconia morphology on methanol synthesis from COand H2 over Cu/ZrO2 catalysts: Part I -- Steady-State Studies

    SciTech Connect (OSTI)

    Rhodes, Michael J.; Bell, Alexis T.

    2005-03-21

    The effect of zirconia phase on the activity and selectivityof Cu/ZrO2 for the hydrogenation of CO has been investigated. Relativelypure t-ZrO2 and m-ZrO2 were prepared with high surface areas (~; 145m2/g). Copper was then deposited onto the surface of these materials byeither incipient-wetness impregnation or deposition-precipitation. For afixed Cu surface area, Cu/m-ZrO2 was tenfold more active for methanolsynthesis than Cu/t-ZrO2 from a feed of 3/1 H2/CO at 3.0 MPa andtemperatures between 473 and 523 K. Cu/m-ZrO2 also exhibited a higherselectivity to methanol. Increasing the Cu surface area on m-ZrO2resulted in further improvement in activity with minimal change inselectivity. Methanol productivity increased linearly for both Cu/t-ZrO2and Cu/m-ZrO2 with increasing Cu surface area. The difference in inherentactivity of each phase paralleled the stronger and larger CO adsorptioncapacity of the Cu/m-ZrO2 as quantified by CO-TPD. The higher COadsorption capacity of Cu/m-ZrO2 is attributed to the presence of a highconcentration of anionic vacancies on the surface of m-ZrO2. Suchvacancies expose cus-Zr4+ cations, which act as Lewis acid centers andenhance the Bronsted acidity of adjacent Zr-OH groups. The presence ofcus-Zr4+ sites and adjacent Bronsted acidic Zr-OH groups contributes tothe adsorption of CO as HCOO-Zr groups, which are the initial precursorsto methanol.

  3. Investigação de parâmetros hiperfinos dos óxidos semicondutores $SnO_{2}$ e $TiO_{2}$ puros e dopados com metais de transição 3d pela espectroscopia de correlação angular gama-gama perturbada

    E-Print Network [OSTI]

    Schell, Juliana

    This study aimed the use of nuclear technique Perturbed ?-? Angular Correlation Spectroccopy (PAC) to measure the hyperfine interactions in thin films and powder samples of SnO2 and TiO2 pure and doped with transition metals to obtain a systematic investigation of defects and magnetism from an atomic point of view with the main motivation the application in spintronics. The work also focused on the preparation and characterization of samples by conventional techniques such as X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy and magnetization measurements. Pure samples of the films were measured by the systematic variation of thermal treatment and applied magnetic field. These measurements were performed in HISKP at the University of Bonn (Rheinische Friedrich-Wilhelms-Universität Bonn) using 111In(111Cd) or 181Hf (181Ta); at IPEN, in turn, these measurements were performed after the diffusion of the same probe nuclei. Another part of PAC measurements were carried out using 11...

  4. M3,,PO4...2-Nanoparticle-Coated LiCoO2 vs LiCo0.96M0.04O2 ,,M = Mg and Zn... on Electrochemical and Storage

    E-Print Network [OSTI]

    Cho, Jaephil

    , 2008. At present, LiCoO2 powders are the most widely used cathode material in Li-ion batteries for mobile electronics, which alter the charge cutoff voltage from 4.2 V vs graphite 4.3 V vs lithium metal to 4.4 V vs graphite 4.5 V vs lithium metal . By increas- ing the cutoff voltage, the energy density

  5. Epitaxial single-crystal thin films of MnxTi1-xO2-? grown on (rutile)TiO2 substrates with pulsed laser deposition: Experiment and theory

    SciTech Connect (OSTI)

    Ilton, Eugene S.; Droubay, Timothy C.; Chaka, Anne M.; Kovarik, Libor; Varga, Tamas; Arey, Bruce W.; Kerisit, Sebastien N.

    2015-02-01

    Epitaxial rutile-structured single-crystal MnxTi1-xO2-? films were synthesized on rutile- (110) and -(001) substrates using pulsed laser deposition. The films were characterized by reflection high-energy electron diffraction (RHEED), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and aberration-corrected transmission electron microscopy (ACTEM). Under the present conditions, 400oC and PO2 = 20 mTorr, single crystal epitaxial thin films were grown for x = 0.13, where x is the nominal average mole fraction of Mn. In fact, arbitrarily thick films could be grown with near invariant Mn/Ti concentration profiles from the substrate/film interface to the film surface. In contrast, at x = 0.25, Mn became enriched towards the surface and a secondary nano-scale phase formed which appeared to maintain the basic rutile structure but with enhanced z-contrast in the tunnels, or tetrahedral interstitial sites. Ab initio thermodynamic calculations provided quantitative estimates for the destabilizing effect of expanding the ?-MnO2 lattice parameters to those of TiO2-rutile, the stabilizing effect of diluting Mn with increasing Ti concentration, and competing reaction pathways.

  6. Large-Scale Synthesis of Transition-Metal-Doped TiO2 Nanowires with Controllable Overpotential

    SciTech Connect (OSTI)

    Liu, Bin; Chen, HaoMing; Liu, Chong; Andrews, Sean; Han, Chris; Yang, Peidong

    2013-03-13

    Practical implementation of one-dimensional semiconductors into devices capable of exploiting their novel properties is often hindered by low product yields, poor material quality, high production cost, or overall lack of synthetic control. Here, we show that a molten-salt flux scheme can be used to synthesize large quantities of high-quality, single-crystalline TiO2 nanowires with controllable dimensions. Furthermore, in situ dopant incorporation of various transition metals allows for the tuning of optical, electrical, and catalytic properties. With this combination of control, robustness, and scalability, the molten-salt flux scheme can provide high-quality TiO2 nanowires to satisfy a broad range of application needs from photovoltaics to photocatalysis.

  7. Salt-Bridge Transition State for the Charge Separation 2+ f CoOH(H2O)2

    E-Print Network [OSTI]

    Metz, Ricardo B.

    Salt-Bridge Transition State for the Charge Separation Co(H2O)4 2+ f CoOH(H2O)2 + + H3O+ Martin K centers form a Co2+ -OH- -H3O+ salt bridge, lowering the barrier for the reaction. The transition state that this reaction proceeds via a salt-bridge transition state.11 The barrier height is directly determined

  8. Identification of the Active Species in Photochemical Hole Scavenging Reactions of Methanol on TiO2

    SciTech Connect (OSTI)

    Shen, Mingmin; Henderson, Michael A.

    2011-11-03

    Molecular and dissociative methanol adsorption species were prepared on rutile TiO2(110) surfaces to study photocatalytic oxidation of methanol in ultrahigh vacuum (UHV) using temperature-programmed desorption (TPD). Adsorbed methoxy groups (CH3O-) were found to be the photoactive form of adsorbed methanol converted to adsorbed formaldehyde and a surface OH group by hole-mediated C-H bond cleavage. These results suggest that adsorbed methoxy is the effective hole scavenger in photochemical reactions involving methanol.

  9. Low Temperature Atomic LayerLow Temperature Atomic Layer Deposition of Tin Dioxide, SnO2

    E-Print Network [OSTI]

    p electrical properties applications Harvard University 2 #12;SnO2: Transparent Conductor and Heat Mirror Hi h i ibl t i i (hi h b d (E 4 1 V)High visible transmission (high bandgap (Eg ~ 4.1 eV) High.06 0.08 0.10 n=1-T-R 0 0 0.2 0.4 Transmission 0.00 0.02 0.04 absorption 200 400 600 800 0

  10. Continuous-wave laser oscillation on the 1315 nm transition of atomic iodine pumped by O2,,a1

    E-Print Network [OSTI]

    Kushner, Mark

    of atomic iodine in favor of the I 2 P1/2 state. The laser output power was 220 mW in a stable cavityContinuous-wave laser oscillation on the 1315 nm transition of atomic iodine pumped by O2,,a11/2 I 2 P3/2 transition of atomic iodine is conventionally obtained by a near-resonant energy

  11. A VUV photoionization measurement and ab-initio calculation of the ionization energy of gas phase SiO2

    SciTech Connect (OSTI)

    Kostko, Oleg; Ahmed, Musahid; Metz, Ricardo B.

    2008-12-05

    In this work we report on the detection and vacuum-ultraviolet (VUV) photoionization of gas phase SiO2 generated in situ via laser ablation of silicon in a CO2 molecular beam. The resulting species are investigated by single photon ionization with tunable VUV synchrotron radiation and mass analyzed using reflectron mass spectrometry. Photoionization efficiency (PIE) curves are recorded for SiO and SiO2 and ionization energy estimates are revealed from such measurements. A state-to-state ionizationenergy of 12.60 (+-0.05) eV is recorded by fitting two prominent peaks in the PIE curve for the following process: 1SUM O-Si-O --> 2PRODg [O-Si-O]+. Electronic structure calculations aid in the interpretation of the photoionization process and allow for identification of the symmetric stretch of 2PRODg [O-Si-O]+ which is observed in the PIE spectrum to be 0.11 eV (890 cm-1) above the ground state of the cation and agrees with the 892 cm-1 symmetric stretch frequency calculated at the CCSD(T)/aug-cc-pVTZ level.

  12. Remediation of Organic and Inorganic Arsenic Contaminated Groundwater using a Nonocrystalline TiO2 Based Adsorbent

    SciTech Connect (OSTI)

    Jing, C.; Meng, X; Calvache, E; Jiang, G

    2009-01-01

    A nanocrystalline TiO2-based adsorbent was evaluated for the simultaneous removal of As(V), As(III), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) in contaminated groundwater. Batch experimental results show that As adsorption followed pseudo-second order rate kinetics. The competitive adsorption was described with the charge distribution multi-site surface complexation model (CD-MUSIC). The groundwater containing an average of 329 ?g L-1 As(III), 246 ?g L-1 As(V), 151 ?g L-1 MMA, and 202 ?g L-1 DMA was continuously passed through a TiO2 filter at an empty bed contact time of 6 min for 4 months. Approximately 11 000, 14 000, and 9900 bed volumes of water had been treated before the As(III), As(V), and MMA concentration in the effluent increased to 10 ?g L-1. However, very little DMA was removed. The EXAFS results demonstrate the existence of a bidentate binuclear As(V) surface complex on spent adsorbent, indicating the oxidation of adsorbed As(III). A nanocrystalline TiO2-based adsorbent could be used for the simultaneous removal of As(V), As(III), MMA, and DMA in contaminated groundwater.

  13. Site Competition During Coadsorption of Acetone with Methanol and Water on TiO2(110)

    SciTech Connect (OSTI)

    Shen, Mingmin; Henderson, Michael A.

    2011-08-02

    The competitive interaction between acetone and two solvent molecules (methanol and water) for surface sites on rutile TiO2(110) was studied using temperature programmed desorption (TPD). On a vacuum reduced TiO2(110) surface, which possessed ~5% oxygen vacancy sites, excess methanol displaced preadsorbed acetone molecules to weakly bound and physisorbed desorption states below 200 K, whereas acetone was stabilized to 250 K against displacement by methanol on an oxidized surface through formation of an acetone-diolate species. These behaviors of acetone differ from the competitive interactions between acetone and water in that acetone is less susceptible to displacement by water. Examination of acetone+methanol and acetone+water multilayer combinations shows that acetone is more compatible in water-ice films than in methanol-ice films, presumably because water has greater potential as a hydrogen-bond donor than does methanol. Acetone molecules displaced from the TiO2(110) surface by water are more likely to be retained in the near-surface region, having a greater opportunity to revisit the surface, than when methanol is used as a coadsorbate. This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  14. Equivalent Circuit Description of Non-compensated n-p Codoped TiO2 as Intermediate Band Solar Cells

    E-Print Network [OSTI]

    Tian-Li Feng; Guang-Wei Deng; Yi Xia; Feng-Cheng Wu; Ping Cui; Hai-Ping Lan; Zhen-Yu Zhang

    2010-12-09

    The novel concept of non-compensated n-p codoping has made it possible to create tunable intermediate bands in the intrinsic band gap of TiO2, making the codoped TiO2 a promising material for developing intermediate band solar cells (IBSCs). Here we investigate the quantum efficiency of such IBSCs within two scenarios - with and without current extracted from the extended intermediate band. Using the ideal equivalent circuit model, we find that the maximum efficiency of 57% in the first scenario and 53% in the second are both much higher than the Shockley-Queisser limit from single gap solar cells. We also obtain various key quantities of the circuits, a useful step in realistic development of TiO2 based solar cells invoking device integration. These equivalent circuit results are also compared with the efficiencies obtained directly from consideration of electron transition between the energy bands, and both approaches reveal the intriguing existence of double peaks in the maximum quantum efficiency as a function of the relative location of IBs.

  15. Compatibility of Lithium Salts with Solvent of the Non-Aqueous Electrolyte in Li–O2 Batteries

    SciTech Connect (OSTI)

    Du, Peng; Lu, Jun; Lau, Kah Chun; Luo, Xiangyi; Bareno, Javier; Zhang, Xiaoyi; Ren, Yang; Zhang, Zhengcheng; Curtiss, Larry A.; Sun, Yang-Kook; Amine, Khalil

    2013-02-20

    The stability of lithium salts, especially in the presence of reduced oxygen species, O2 and H2O (even in a small amount), plays an important role in the cyclability and capacity of Li–O2 cells. This combined experimental and computational study provides evidence that the stability of the electrolyte used in Li–O2 cells strongly depends on the compatibility of lithium salts with solvent. In the case of the LiPF6–1NM3 electrolyte, the decomposition of LiPF6 occurs in the cell as evidenced by in situ XRD, FT-IR and XPS analysis, which triggers the decomposition of 1NM3 solvent due to formation of HF from the decomposition of LiPF6. These reactions lead to degradation of the electrolyte and cause poor cyclability of the cell. The same reactions are not observed when LiTFSI and LiCF3SO3 are used as the lithium salts in 1NM3 solvent, or LiPF6 is used in TEGDME solvent.

  16. Modeling of selected ceramic processing parameters employed in the fabrication of 238PuO2 fuel pellets

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Brockman, R. A.; Kramer, D. P.; Barklay, C. D.; Cairns-Gallimore, D.; Brown, J. L.; Huling, J. C.; Van Pelt, C. E.

    2011-10-01

    Recent deep space missions utilize the thermal output of the radioisotope plutonium-238 as the fuel in the thermal to electrical power system. Since the application of plutonium in its elemental state has several disadvantages, the fuel employed in these deep space power systems is typically in the oxide form such as plutonium-238 dioxide (238PuO2). As an oxide, the processing of the plutonium dioxide into fuel pellets is performed via ''classical'' ceramic processing unit operations such as sieving of the powder, pressing, sintering, etc. Modeling of these unit operations can be beneficial in the understanding and control of processing parameters withmore »the goal of further enhancing the desired characteristics of the 238PuO2 fuel pellets. A finite element model has been used to help identify the time-temperature-stress profile within a pellet during a furnace operation taking into account that 238PuO2 itself has a significant thermal output. The results of the modeling efforts will be discussed.« less

  17. Design and Tailoring of a Three-Dimensional TiO2-Graphene-Carbon Nanotube Nanocomposite for Fast Lithium Storage

    E-Print Network [OSTI]

    Cao, Guozhong

    and thereby is inherently safe by avoiding Li electroplating. Furthermore, the TiO2 has high reversible,12,13 and coat the TiO2 particles with an electron-conducting layer.7,9,14,15 The hybrid nanostructure electrode

  18. Mesoporous TiO2 beads for high efficiency CdS/ CdSe quantum dot co-sensitized solar cells

    E-Print Network [OSTI]

    Cao, Guozhong

    Mesoporous TiO2 beads for high efficiency CdS/ CdSe quantum dot co-sensitized solar cells Ru Zhou-sensitized solar cell (QDSC) application. The photoanode films were composed of submicrometer-sized beads consisting of packed TiO2 nanocrystallites. A power conversion efficiency up to 4.05% has been achieved

  19. Enhancement of light extraction efficiency of InGaN quantum wells light emitting diodes using SiO2/polystyrene microlens arrays

    E-Print Network [OSTI]

    Gilchrist, James F.

    in the Fresnel reflection. Improvement of output power by 219% for InGaN quantum wells LEDs emitting at peakGaN quantum wells light emitting diodes LEDs using SiO2/polystyrene microspheres was demonstrated experimentally. The utilization of SiO2/polystyrene microlens arrays on InGaN quantum wells LEDs, deposited via

  20. Shock-Tube Time-History Measurements of H2O in the H2/O2 System Using IR Laser Absorption Spectroscopy 

    E-Print Network [OSTI]

    Mulvihill, Clayton

    2015-05-04

    H2O time-histories were studied within the H2/O2 system using a tunable diode laser system and a pressure-driven shock tube. Stoichiometric H2/O2 mixtures were prepared in high amounts of argon dilution. The mixtures were heated using a shock tube...

  1. Generation of Realistic Amorphous Al2O3 And ZrO2 Samples By Hybrid Classical and First-Principle Molecular Dynamics Simulations

    E-Print Network [OSTI]

    Kummel, Andrew C.

    Generation of Realistic Amorphous Al2O3 And ZrO2 Samples By Hybrid Classical and First-ZrO2 were generated by a hybrid classical and density functional theory (DFT) "melt and quench" molecular dynamics approach. The generated samples demonstrated good correlation with reference experimental

  2. 1 Rectangular Bunched Rutile TiO2 Nanorod Arrays Grown on Carbon 2 Fiber for Dye-Sensitized Solar Cells

    E-Print Network [OSTI]

    Wang, Zhong L.

    a study of rectangular bunched 13 TiO2 nanorod (NR) arrays grown on carbon fibers (CFs) 14 from titanium are fabricated by using etched TiO2 18 NR-coated CFs as the photoanode. An absolute energy 19 conversion (CFs). Relative to the traditional photoanode, CFs are 47 flexible, conductive, and stable in liquid

  3. Characterization of the natural barriers of intergranular tunnel junctions: Cr2O3 surface layers on CrO2 nanoparticles

    E-Print Network [OSTI]

    Diebold, Ulrike

    thin native oxide layer with a thickness of 1­3 nm on the surface of CrO2 powders has been observed direct observation by TEM of a 1­3 nm thick native oxide layer on the surface of the CrO2 single crystal

  4. Atomic imaging and modeling of H2O2(g) surface passivation, functionalization, and atomic layer deposition nucleation on the Ge(100) surface

    E-Print Network [OSTI]

    Kummel, Andrew C.

    and unpinning of a compound semiconductor surface during atomic layer deposition J. Chem. Phys. 133, 154704 and modeling of H2O2(g) surface passivation, functionalization, and atomic layer deposition nucleation, functionalization, and atomic layer deposition nucleation via H2O2(g) and trimethylalu- minum (TMA) dosing

  5. A Novel Combustion Synthesis Preparation of CuO/ZnO/ZrO2/Pd for Oxidative Hydrogen Production from Methanol

    E-Print Network [OSTI]

    Mukasyan, Alexander

    , selectively forming hydrogen and carbon mon- oxide [5­8]. However, when palladium is prepared with ZnO or ZrO2A Novel Combustion Synthesis Preparation of CuO/ZnO/ZrO2/Pd for Oxidative Hydrogen Production from Abstract Complex catalysts containing combinations of copper, zinc, zirconium, and palladium oxides were

  6. Influence of in-plane and bridging oxygen vacancies of SnO_2 nanostructures on CH_4 sensing at low operating temperatures

    E-Print Network [OSTI]

    Bonu, Venkataramana; Prasad, Arun K; Krishna, Nanda Gopala; Dhara, Sandip; Tyagi, A K

    2015-01-01

    Role of 'O' defects in sensing pollutant with nanostructured SnO_2 is not well understood, especially at low temperatures. SnO_2 nanoparticles were grown by soft chemistry route followed by subsequent annealing treatment under specific conditions. Nanowires were grown by chemical vapor deposition technique. A systematic photoluminescence (PL) investigation of 'O' defects in SnO_2 nanostructures revealed a strong correlation between shallow donors created by the in-plane and the bridging 'O' vacancies and gas sensing at low temperatures. These SnO_2 nanostructures detected methane (CH_4), a reducing and green house gas at a low temperature of 50 ^oC. Response of CH_4 was found to be strongly dependent on surface defect in comparison to surface to volume ratio. Control over 'O' vacancies during the synthesis of SnO2 nanomaterials, as supported by X-ray photoelectron spectroscopy and subsequent elucidation for low temperature sensing are demonstrated.

  7. Radiation damage in cubic-ZrO2 and yttria-stabilized zirconia from molecular dynamics simulations

    SciTech Connect (OSTI)

    Aidhy, Dilpuneet S; Zhang, Yanwen; Weber, William J

    2015-01-01

    We perform molecular dynamics simulation on cubic ZrO2 and yttria-stabilized zirconia (YSZ) to elucidate defect cluster formation resulting from radiation damage, and evaluate the impact of Y-dopants. Interstitial clusters composed of split-interstitial building blocks, i.e., Zr-Zr or Y-Zr are formed. Oxygen vacancies control cation defect migration; in their presence, Zr interstitials aggregate to form split-interstitials whereas in their absence Zr interstitials remain immobile, as isolated single-interstitials. Y-doping prevents interstitial cluster formation due to sequestration of oxygen vacancies.

  8. Ab Initio Simulation of Charge Transfer at the Semiconductor Quantum Dot/TiO 2 Interface in Quantum Dot-Sensitized Solar Cells

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xin, Xukai; Li, Bo; Jung, Jaehan; Yoon, Young Jun; Biswas, Rana; Lin, Zhiqun

    2014-07-24

    Quantum dot-sensitized solar cells (QDSSCs) have emerged as a promising solar architecture for next-generation solar cells. The QDSSCs exhibit a remarkably fast electron transfer from the quantum dot (QD) donor to the TiO2 acceptor with size quantization properties of QDs that allows for the modulation of band energies to control photoresponse and photoconversion efficiency of solar cells. In order to understand the mechanisms that underpin this rapid charge transfer, the electronic properties of CdSe and PbSe QDs with different sizes on the TiO2 substrate are simulated using a rigorous ab initio density functional method. Our method capitalizes on localized orbitalmore »basis set, which is computationally less intensive. Quite intriguingly, a remarkable set of electron bridging states between QDs and TiO2 occurring via the strong bonding between the conduction bands of QDs and TiO2 is revealed. Such bridging states account for the fast adiabatic charge transfer from the QD donor to the TiO2 acceptor, and may be a general feature for strongly coupled donor/acceptor systems. All the QDs/TiO2 systems exhibit type II band alignments, with conduction band offsets that increase with the decrease in QD size. This facilitates the charge transfer from QDs donors to TiO2 acceptors and explains the dependence of the increased charge transfer rate with the decreased QD size.« less

  9. Multifunctional Properties of Cyanate Ester Composites with SiO2 Coated Fe3O4 Fillers

    SciTech Connect (OSTI)

    Sun, Weixing; Sun, Wuzhu; Kessler, Michael R.; Bowler, Nicola; Dennis, Kevin W.; McCallum, R. William; Li, Qi; Tan, Xiaoli

    2013-02-22

    SiO2 coated Fe3O4 submicrometer spherical particles (a conducting core/insulating shell configuration) are fabricated using a hydrothermal method and are loaded at 10 and 20 vol % into a bisphenol E cyanate ester matrix for synthesis of multifunctional composites. The dielectric constant of the resulting composites is found to be enhanced over a wide frequency and temperature range while the low dielectric loss tangent of the neat cyanate ester polymer is largely preserved up to 160 ?C due to the insulating SiO2 coating on individual conductive Fe3O4 submicrometer spheres. These composites also demonstrate high dielectric breakdown strengths at room temperature. Dynamic mechanical analysis indicates that the storage modulus of the composite with a 20 vol % filler loading is twice as high as that of neat resin, but the glass transition temperature considerably decreases with increasing filler content. Magnetic measurements reveal a large saturation magnetization and negligibly low coercivity and remanent magnetization in these composites.

  10. Modeling Excited States in TiO2 Nanoparticles: On the Accuracy of a TD-DFT Based Description

    SciTech Connect (OSTI)

    Berardo, Enrico; Hu, Hanshi; Shevlin, S. A.; Woodley, Scott M.; Kowalski, Karol; Zwijnenburg, Martijn A.

    2014-03-11

    We have investigated the suitability of Time-Dependent Density Functional Theory (TD-DFT) to describe vertical low-energy excitations in naked and hydrated titanium dioxide nanoparticles through a comparison with results from Equation-of-Motion Coupled Cluster (EOM-CC) quantum chemistry methods. We demonstrate that for most TiO2 nanoparticles TD-DFT calculations with commonly used exchange-correlation (XC-)potentials (e.g. B3LYP) and EOM-CC methods give qualitatively similar results. Importantly, however, we also show that for an important subset of structures, TD-DFT gives qualitatively different results depending upon the XC-potential used and that in this case only TD-CAM-B3LYP and TD-BHLYP calculations yield results that are consistent with those obtained using EOM-CC theory. Moreover, we demonstrate that the discrepancies for such structures arise from a particular combination of defects, excitations involving which are charge-transfer excitations and hence are poorly described by XC-potentials that contain no or low fractions of Hartree-Fock like exchange. Finally, we discuss that such defects are readily healed in the presence of ubiquitously present water and that as a result the description of vertical low-energy excitations for hydrated TiO2 nanoparticles is hence non-problematic.

  11. CALDER - Neutrinoless double-beta decay identification in TeO$_2$ bolometers with kinetic inductance detectors

    E-Print Network [OSTI]

    E. S. Battistelli; F. Bellini; C. Bucci; M. Calvo; L. Cardani; N. Casali; M. G. Castellano; I. Colantoni; A Coppolecchia; C. Cosmelli; A. Cruciani; P. de Bernardis; S. Di Domizio; A. D'Addabbo; M. Martinez; S. Masi; L. Pagnanini; C. Tomei; M. Vignati

    2015-05-19

    Next-generation experiments searching for neutrinoless double-beta decay must be sensitive to a Majorana neutrino mass as low as 10 meV. CUORE, an array of 988 TeO$_2$ bolometers being commissioned at Laboratori Nazionali del Gran Sasso in Italy, features an expected sensitivity of 50-130 meV at 90% C.L, that can be improved by removing the background from $\\alpha$ radioactivity. This is possible if, in coincidence with the heat release in a bolometer, the Cherenkov light emitted by the $\\beta$ signal is detected. The amount of light detected is so far limited to only 100 eV, requiring low-noise cryogenic light detectors. The CALDER project (Cryogenic wide-Area Light Detectors with Excellent Resolution) aims at developing a small prototype experiment consisting of TeO$_2$ bolometers coupled to new light detectors based on kinetic inductance detectors. The R&D is focused on the light detectors that could be implemented in a next-generation neutrinoless double-beta decay experiment.

  12. Impedance spectroscopy study of SiO2-Li2O:Nd2O3 glasses

    SciTech Connect (OSTI)

    Pereia, R.; Gozzo, C B; Guedes, I.; Boatner, Lynn A; Terezo, A J; Costa, M M

    2014-01-01

    In the present study, neodymium-doped lithium silicate glasses have been prepared by the conventional melt-quenching technique. The dielectric properties, electric modulus and electrical conductivity of SiO2-Li2O (SiLi-0Nd) and SiO2-Li2O:Nd2O3 (SiLi-1.35Nd) have been studied from 1 Hz to 1 MHz in the 333 423 K temperature range. At a given temperature and frequency, we observe that the resistivity increases while the conductivity accordingly decreases when neodymium ions are added to the glass matrix. The activation energy of two distinct regions was evaluated from the ln( dc)=f(1/T) plot and was found to be E1(T<363K)=0.61(0.66)eV and E2(T>363K)=1.26(1.09)eV for SiLi-0Nd (SiLi-1,35Nd). The dielectric constant ( Re) decreases while the dielectric loss (tan ( )) increases under Nd2O3 doping. We also observe that for both glasses, Re and tan ( ) tend to increase with increasing temperature and decrease with increasing frequency.

  13. The PMMA opal film was infiltrated with SiO2 using a homemade CVD setup operating at atmospheric pressure and room temperature

    E-Print Network [OSTI]

    The PMMA opal film was infiltrated with SiO2 using a homemade CVD setup operating at atmospheric. HRSEM was used to observe the alterations in the opal structure. Before examination, samples had been

  14. High ethanol sensitivity of Palladium/TiO2 nanobelt surface heterostructures dominated by enlarged surface area and nano-Schottky junctions

    E-Print Network [OSTI]

    Cao, Guozhong

    High ethanol sensitivity of Palladium/TiO2 nanobelt surface heterostructures dominated by enlarged [1­3], lithium-ion batteries [4,5], chemical and bio-sensors [6,7], hydrogen production and storage

  15. One-pot synthesis of poly(3,4-ethylenedioxythiophene)-Pt nanoparticle composite and its application to electrochemical H2O2 sensor

    E-Print Network [OSTI]

    Chang, Li-Chi; Wu, Huan-Nung; Lin, Chia-Yu; Lai, Yi-Hsuan; Hu, Chih-Wei; Ho, Kuo-Chuan

    2012-06-20

    Abstract Poly(3,4-ethylenedioxythiophene)-Pt nanoparticle composite was synthesized in one-pot fashion using a photo-assisted chemical method, and its electrocatalytic properties toward hydrogen peroxide (H2O2) was investigated. Under UV irradiation...

  16. Effect of cerium incorporation into zirconia on the activity ofCu/ZrO2 for methanol synthesis via CO hydrogenation

    SciTech Connect (OSTI)

    Pokrovski, Konstantin A.; Rhodes, Michael D.; Bell, Alexis T.

    2005-08-24

    The effects of Ce incorporation into ZrO2 on the catalyticperformance of Cu/ZrO2 for the hydrogenation of CO have beeninvestigated. A Ce0.3Zr0.7O2 solid solution was synthesized by forcedhydrolysis at low pH. After calcination at 873 K, XRD and Ramanspectroscopy characterization indicated that the Ce0.3Zr0.7O2 had a t''crystal structure. 1.2 wt percent Cu/Ce0.3Zr0.7O2 exhibited H2consumption peaks at low temperature (<473 K) during H2-TPRindicating a significant fraction (~; 70 percent) of Ce4+ is reduced toCe3+. 1.2 wt percent Cu/Ce0.3Zr0.7O2 is 2.7 times more active formethanol synthesis than 1.2 wt percent Cu/m-ZrO2 at 3.0 MPa attemperatures between 473 and 523 K and exhibits a higher selectivity tomethanol. In-situ infrared spectroscopy shows that, analogous toCu/m-ZrO2, the primary surface species on Cu/Ce0.3Zr0.7O2 during COhydrogenation are formate and methoxide species. A shift in the bandposition of the bridged methoxide species indicated that some of thesegroups were bonded to both Zr4+ and Ce3+ cations. For both catalysts, therate-limiting step for methanol synthesis is the reductive elimination ofmethoxide species. The higher rate of methanol synthesis onCu/Ce0.3Zr0.7O2 relative to Cu/m-ZrO2 was primarily due to a ~; 2.4 timeshigher apparent rate constant, kapp, for methoxide hydrogenation, whichis attributed to the higher surface concentration of H atoms on theformer catalyst. The increased capacity of the Ce-containing catalyst isattributed to interactions of H atoms with Ce-O pairs present at thesurface of the oxide phase.

  17. Thiolate ligands as a double-edged sword for CO oxidation on CeO2-supported Au25(SR)18 nanoclusters

    SciTech Connect (OSTI)

    Wu, Zili [ORNL; Jiang, Deen [ORNL; Mann, Amanda K [ORNL; Mullins, David R [ORNL; Qiao, Zhen-an [University of Tennessee, Knoxville (UTK); Allard Jr, Lawrence Frederick [ORNL; Zeng, Chenjie [Carnegie Mellon University (CMU); Jin, Rongchao [Carnegie Mellon University (CMU); Overbury, Steven {Steve} H [ORNL

    2014-01-01

    The effect of thiolate ligands was explored on the catalysis of CeO2-rod supported Au25(SR)18 (SR = -SCH2-CH2-Ph) by using CO oxidation as a probe reaction. Reaction kinetic tests, in situ IR and X-ray absorption spectroscopy, and density functional theory (DFT) were employed to understand how the thiolate ligands affect the nature of active sites, activation of CO and O2, as well as the reaction mechanism and kinetics. The intact Au25(SR)18 on CeO2-rod is found not able to adsorb CO. Only when the thiolate ligands are partially removed, starting from the interface between Au25(SR)18 and CeO2 at temperatures of 423 K and above, can the adsorption of CO be observed by IR. DFT calculations suggest that CO adsorbs favorably on the exposed gold atoms. Accordingly, the CO oxidation light-off temperature shifts to lower temperature. Several types of Au sites are probed by IR of CO adsorption during the ligand removal process. The cationic Au sites (charged between 0 and +1) are found to play the major role for low temperature CO oxidation. Similar activation energy and reaction rate are found for CO oxidation on differently treated Au25(SR)18/CeO2-rod, suggesting a simple site-blocking effect of the thiolate ligands in Au nanoclusters catalysis. Isotopic labelling experiments clearly indicate that CO oxidation on Au25(SR)18/CeO2-rod proceeds predominantly via the redox mechanism where CeO2 activates O2 while CO is activated on the de-thiolated gold sites. These results points to a double-edged sword role played by the thiolate ligands on Au25 nanoclusters for CO oxidation.

  18. Rechargeable Li/CO2O2 (2 : 1) battery and Li/CO2 Yali Liu, Rui Wang, Yingchun Lyu, Hong Li* and Liquan Chen

    E-Print Network [OSTI]

    Wang, Wei Hua

    under suitable conditions. Therefore, it is plausible that a recharge- able Li/CO2 battery couldRechargeable Li/CO2­O2 (2 : 1) battery and Li/CO2 battery Yali Liu, Rui Wang, Yingchun Lyu, Hong Li* and Liquan Chen A Li/CO2­O2 (2 : 1, volume ratio) battery and a Li/CO2 battery with discharging specific

  19. DFT+U Study of Polaronic Conduction in Li2O2 and Li2CO3: Implications for Li-Air Batteries

    E-Print Network [OSTI]

    Thygesen, Kristian

    DFT+U Study of Polaronic Conduction in Li2O2 and Li2CO3: Implications for Li-Air Batteries J. M-air batteries are known to be Li2O2 and residual Li2CO3. Recent experiments indicate that the charge transport through these materials is the main limiting factor for the battery performance. It has been also shown

  20. Design of 7 wt.% Y2O3-ZrO2/Mullite Plasma-Sprayed Composite Coatings for Increased Creep Resistance

    E-Print Network [OSTI]

    Trice, Rodney W.

    Design of 7 wt.% Y2O3-ZrO2/Mullite Plasma-Sprayed Composite Coatings for Increased Creep Resistance of the American Ceramic Society #12;2 Abstract Plasma-sprayed stand-alone coatings of 7 wt.% Y2O3-ZrO2 (YSZ three coating types in the as-sprayed condition at stresses from 40-80 MPa and temperatures of 1000

  1. Investigation of Pt, Pt3Co, and Pt3CoMo Cathodes for the ORR in a Microfluidic H2O2 Fuel Cell

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    Investigation of Pt, Pt3Co, and Pt3CoÕMo Cathodes for the ORR in a Microfluidic H2ÕO2 Fuel Cell on the performance and durability of four Pt-based cathode catalysts in a microfluidic H2/O2 fuel cell: commercial performed using an acidic microfluidic H2/O2 fuel cell with an analytical platform. The electrolyte flow

  2. Electrode Materials with the Na0.44MnO2 Structure: Effect ofTitanium Substitution on Physical and Electrochemical Properties

    SciTech Connect (OSTI)

    Doeff, Marca M; Saint, Juliette A.; Doeff, Marca M; Wilcox, James D.

    2008-03-10

    The physical and electrochemical properties of LixMnO2 and LixTi0.11Mn0.89O2 synthesized from precursors made by glycine-nitrate combustion (GNC) and solid-state synthesis methods (SS) are examined in this paper. The highest specific capacities in lithium cells are obtained for SS-LixMnO2 electrodes at low current densities, but GNC-LixTi0.11Mn0.89O2 electrodes show the best high rate performance. These results can be explained by changes in the voltage characteristics and differences in the particle morphologies induced by the Ti-substitution and synthesis method. Ti-substitution also results in a decrease in the electronic conductivity, but greatly improves the thermal properties and imparts dissolution resistance to the electrode. For these reasons, it is preferable to use LixTi0.11MnO0.89O2 in lithium battery configurations rather than LixMnO2. Suggestions for improving the electrochemical performance of the Ti-substituted variant are given based on the results described herein.

  3. Photoelectrochemical and photocatalytic properties of N + S co-doped TiO2 nanotube array films under visible light irradiation

    E-Print Network [OSTI]

    Yan, Guotian; Houa, Jian; Yang, Jianjun; 10.1016/j.matchemphys.2011.04.063

    2011-01-01

    In this paper, we report on the co-doping nitrogen and sulfur has been achieved in the TiO2 nanotube array films by treatment with thiourea and calcination under vacuum at 500 {\\deg}C for 3 h. The samples were characterized by scanning electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy. XPS spectra revealed that N might coexist in the forms of NTiO and NOTi, S was incorporated into the lattice of TiO2 through substituting oxygen atoms in the N + S co-doped TiO2 nanotube array films. XRD patterns indicated that improved crystallinity was obtained for N + S co-doped TiO2 nanotube arrays as compared to that of undoped TiO2 nanotube arrays. In photoelectrochemical measurements, the photocurrent of N + S co-doped TiO2 nanotube array films was greatly enhanced compared to that of undoped samples under visible light irradiation. And the photocatalytic activities of the samples were evaluated on the removal of methylene blue un...

  4. Lithium Salts for Advanced Lithium Batteries: Li-metal, Li-O2, and Li-S

    SciTech Connect (OSTI)

    Younesi, Reza; Veith, Gabriel M; Johansson, Patrik; Edstrom, Kristina; Vegge, Tejs

    2015-01-01

    Presently lithium hexafluorophosphate (LiPF6) is the dominant Li-salt used in commercial rechargeable lithium-ion batteries (LIBs) based on a graphite anode and a 3-4 V cathode material. While LiPF6 is not the ideal Li-salt for every important electrolyte property, it has a uniquely suitable combination of properties (temperature range, passivation, conductivity, etc.) rendering it the overall best Li-salt for LIBs. However, this may not necessarily be true for other types of Li-based batteries. Indeed, next generation batteries, for example lithium-metal (Li-metal), lithium-oxygen (Li-O2), and lithium sulphur (Li-S), require a re-evaluation of Li-salts due to the different electrochemical and chemical reactions and conditions within such cells. This review explores the critical role Li-salts play in ensuring in these batteries viability.

  5. Performance of a large TeO2 crystal as a cryogenic bolometer in searching for neutrinoless double beta decay

    E-Print Network [OSTI]

    L. Cardani; L. Gironi; J. W. Beeman; I. Dafinei; Z. Ge; G. Pessina; S. Pirro; Y. Zhu

    2011-06-03

    Bolometers are ideal devices in the search for neutrinoless Double Beta Decay. Enlarging the mass of individual detectors would simplify the construction of a large experiment, but would also decrease the background per unit mass induced by alpha-emitters located close to the surfaces and background arising from external and internal gamma's. We present the very promising results obtained with a 2.13 kg TeO2 crystal. This bolometer, cooled down to a temperature of 10.5 mK in a dilution refrigerator located deep underground in the Gran Sasso National Laboratories, represents the largest thermal detector ever operated. The detector exhibited an energy resolution spanning a range from 3.9 keV (at 145 keV) to 7.8 keV (at the 2615 gamma-line of 208Tl) FWHM. We discuss the decrease in the background per unit mass that can be achieved increasing the mass of a bolometer.

  6. Alternation of the Pd Lattice in Nano-Sized-Pd/ZrO2 Composite during Hydrogen Absorption

    SciTech Connect (OSTI)

    Arachi, Yoshinori; Asai, Takeshi; Emura, Shuichi; Omura, Akira; Nunogaki, Masanobu; Yamaura, Shunichi; Inoue, Akihisa; Arata, Yoshiaki

    2007-02-02

    Structural analysis of high Deuterium absorbed 5 nm Pd particles in dispersed ZrO2 has been carried out using XAFS techniques. X-ray absorption spectra around the Pd K-absorption edge were observed and analyzed. The Pd-Pd bonding distance in the fcc Pd lattice was enlarged by 0.08 {approx} 0.09 A during absorption of deuterium, and it completely reverted to its original state with the release of deuterium while maintaining the crystal lattice symmetry. These changes provide evidence that deuterium locates not on the surface of the Pd particle, but rather within the Pd crystal lattice. XANES spectra clearly indicate that any change in the oxidation state of Pd are not observed, resulting in no reaction of the absorbed Deuterium atoms with Pd atoms. This paper reports the alternation of Pd lattice in nano-sized composite during hydrogen absorption. The possible models of deuterium position in the Pd lattice are also discussed.

  7. Sub-cm Resolution Distributed Fiber Optic Hydrogen Sensing with Nano-Engineered TiO2

    E-Print Network [OSTI]

    Poole, Zsolt; Yan, Aidong; Lin, Yuankun; Chen, Kevin

    2015-01-01

    The 3D nano-structuring on the 2) to be reduced and matched with the cladding of optical fiber(n~1.46) for low-loss integration. A high temperature capable hydrogen sensor composed of D-shaped optical fiber with palladium nanoparticles infused nanoporous (~5nm) TiO2 film is demonstrated. The behavior of the developed sensor was characterized by examining the wavelength of an incorporated Fiber Bragg Grating and by observing the transmission losses at temperatures up to 700C. In addition, with frequency domain reflectometry the distributed sensing potential of the developed sensor for hydrogen concentrations of up to 10% is examined. The results show the possibility of detecting chemical gradients with sub-cm resolution at very high temperatures(>500C).

  8. Experimental study of the structure of rich premixed 1,3-butadiene/CH4/O2/Ar flame

    E-Print Network [OSTI]

    Gueniche, Hadj-Ali; Fournet, René; Battin-Leclerc, Frédérique

    2006-01-01

    The structure of a laminar rich premixed 1,3-C4H6/CH4/O2/Ar flame have been investigated. 1,3-Butadiene, methane, oxygen and argon mole fractions are 0.033; 0.2073; 0.3315, and 0.4280, respectively, for an equivalent ratio of 1.80. The flame has been stabilized on a burner at a pressure of 6.7 kPa (50 Torr). The concentration profiles of stable species were measured by gas chromatography after sampling with a quartz probe. Quantified species included carbon monoxide and dioxide, methane, oxygen, hydrogen, ethane, ethylene, acetylene, propyne, allene, propene, cyclopropane, 1,3-butadiene, butenes, 1-butyne, vinylacetylene, diacetylene, C5 compounds, benzene, and toluene. The temperature was measured thanks to a thermocouple in PtRh (6%)-PtRh (30%) settled inside the enclosure and ranged from 900 K close to the burner up to 2100 K.

  9. Hydrodechlorination of 1,2-Dichloroethane Catalyzedby Dendrimer-Derived Pt-Cu/SiO2 Catalysts

    SciTech Connect (OSTI)

    Xie, Hong; Howe, Jane Y; Schwartz, Viviane; Monnier, J. R.; Williams, Christopher T.; Ploehn, Harry J.

    2008-01-01

    Dendrimer-metal-nanocomposites (DMNs) were used as precursors to prepare SiO2 supported monometallic Pt, Cu and bimetallic Pt-Cu catalysts with Pt/Cu atomic ratios of 1:1 (Pt50Cu50) and 1:3 (Pt25Cu75). After impregnation of these DMNs onto the support, the catalysts were thermally treated and activated following an optimized protocol. Scanning transmission electron microscopy (STEM) shows that the metal nanoparticles in dendrimer-derived SiO2-supported catalysts are smaller and have a more narrow size distribution than those in conventional catalysts prepared using corresponding metal salts via the wet impregnation method. Slow deactivation was observed for hydrodechlorination of 1,2-dichloroethane over monometallic Cu catalysts, which showed an activity about one to two orders of magnitude lower than that of the Pt-containing catalysts. Hydrodechlorination of 1,2-dichloroethane over Pt and Pt50Cu50 catalysts mainly produces ethane and the selectivity towards ethane increases with temperature. For Pt25Cu75 catalyst, the selectivity towards ethane decreases in favor of ethylene. The overall activity decreases with increasing Cu loading in the catalysts. Activity based on surface Pt sites suggests the formation of bi-functional surfaces in Pt25Cu75 catalyst favoring C-Cl bond scission on Cu sites and hydrogenation of intermediate .CH2CH2. on Pt sites. Furthermore, kinetic analyses suggest different reaction mechanisms for hydrodechlorination of 1,2-dichloroethane over Pt and Cu-enriched surfaces in the Pt-Cu bimetallic catalysts.

  10. TiO2 Nanotube Arrays Annealed in N2 for Efficient Lithium-Ion Intercalation Dawei Liu, Peng Xiao,, Yunhuai Zhang,, Betzaida B. Garcia, Qifeng Zhang, Qing Guo,|

    E-Print Network [OSTI]

    Cao, Guozhong

    TiO2 Nanotube Arrays Annealed in N2 for Efficient Lithium-Ion Intercalation Dawei Liu, Peng Xiao capacity and improved cyclic stability. TiO2 nanotube arrays annealed at 300 °C exhibited the best lithium capacity decreased, but the cyclic stability improved; 400 °C annealed TiO2 nanotube arrays possessed

  11. Synthesis, Structure, and Electrochemical Performance of High Capacity Li2Cu0.5Ni0.5O2 Cathodes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ruther, Rose E; Zhou, Hui; Dhital, Chetan; Saravanan, Kuppan; Kercher, Andrew K.; Chen, Guoying; Huq, Ashfia; Delnick, Frank M.; Nanda, Jagjit

    2015-09-08

    Orthorhombic Li2NiO2, Li2CuO2, and solid solutions thereof have been studied as potential cathode materials for lithium-ion batteries due to their high theoretical capacity and relatively low cost. While neither endmember shows good cycling stability, the intermediate composition, Li2Cu0.5Ni0.5O2, yields reasonably high reversible capacities. A new synthetic approach and detailed characterization of this phase and the parent Li2CuO2 are presented. The cycle life of Li2Cu0.5Ni0.5O2 is shown to depend critically on the voltage window. The formation of Cu1+ at low voltage and oxygen evolution at high voltage limit the electrochemical reversibility. In situ X-ray absorption spectroscopy (XAS), in situ Raman spectroscopy,more »and gas evolution measurements are used to follow the chemical and structural changes that occur as a function of cell voltage.« less

  12. TiO2 Nanotubes/MWCNTs Nanocomposite Photocatalysts: Synthesis, Characterization and Photocatalytic Hydrogen Evolution Under UV-Vis Light Illumination

    SciTech Connect (OSTI)

    Li, Hao-Peng; Zhang, Xiao-Yan; Cui, Xiao-Li; Lin, Yuehe

    2012-03-01

    Nanocomposite of TiO2 nanotubes (TiO2NTs) and multiwalled carbon nanotubes (MWCNTs) has been synthesized by a hydrothermal method and firstly used in photocatalytic hydrogen production. The obtained TiO2 NTs/MWCNTs composites were characterized by X-ray diffraction, transmission electron microscopy, Raman spectrum and ultraviolet-visible diffuse reflectance spectroscopy. The experimental results revealed that the MWCNTs were decorated with well dispersed anatase TiO2 nanotubes with a diameter of 8-15 nm. A slight blue shift and weak symmetry was observed for the strongest Raman peak which resulted from strain gradients originating from interface integration between TiO2 nanotubes and MWCNTs. The photocatalytic activity of the as-prepared samples was evaluated by hydrogen evolution from water splitting using Na2S and Na2SO3 as sacrificial reagents under UV-vis light irradiation. Enhanced photocatalytic activity compared with P25 has been observed for the resulted samples. The nanocomposite with optimized MWCNTs content of 1% displayed a hydrogen production rate of 161 u mol/h/g. Good photocatalytic stability of the as-synthesized samples was observed as well.

  13. Hydrolysis of ZrCl4 and HfCl4: The Initial Steps in the High-Temperature Oxidation of Metal Chlorides to Produce ZrO2 and HfO2

    SciTech Connect (OSTI)

    Fang, Zongtang; Dixon, David A.

    2013-03-08

    The gas-phase hydrolysis of MCl4 (M = Zr, Hf) to produce the initial particles on the way to zirconia and hafnia nanoparticles has been studied with electronic structure theory. The potential energy surfaces, the themochemistry of the reaction species, and the reaction paths for the initial steps of MCl4 reacting with H2O have been calculated. The hydrolysis of MCl4 at higher temperatures begins with the formation of oxychlorohydroxides followed by the elimination of HCl instead of the direct production of MOCl2 and HCl or MO2 and HCl due to the substantial endothermicities associated with the formation of gas-phase MO2. The structural properties and heats of formation of the reactants and products are consistent with the available experimental results. A number of metal oxychlorides (oxychlorohydroxides) intermediate clusters have been studied to assess their role in the production of MO2 nanoparticles. The calculated clustering reaction energies of those intermediates are highly exothermic, so they could be readily formed in the hydrolysis process. These intermediate clusters can be formed exothermically from metal oxychlorohydroxides by the elimination of one HCl or H2O molecule. Our calculations show that the mechanisms leading to the formation of MO2 nanoparticles are complicated and are accompanied by the potential production of a wide range of intermediates, as found for the production of TiO2 particles from the high-temperature oxidation of TiCl4.

  14. Mechanism of Na2SO4-induced corrosion of molybdenum containing nickel-base superalloys at high temperatures. I. Corrosion in atmospheres containing O2 only. II. Corrosion in O2 + SO2 atmospheres

    SciTech Connect (OSTI)

    Misra, A.K.

    1986-05-01

    Kinetics of the Na2SO4-induced corrosion of the molybdenum-containing nickel-base superalloys, B-1900 and Udimet 700, coated with Na2MoO4, has been studied in oxygen atmosphere at temperatures ranging from 750 to 950 C. Because the gas turbine atmosphere always contains some SO2 and SO3, the effect of atmospheric SO2 content on corrosion of Udimet-700 has also been studied. It was found that in the O2 atmosphere the melt in the catastrophic corrosion phase consists of Na2MoO4 plus MoO3, with the onset of the catastrophic corrosion coinciding with the appearance of MoO3. In the presence of low levels of atmospheric SO2 (below 0.24 percent), the melt during catastrophic corrosion contains, in addition to Na2MoO4 and MoO3, some quantities of Na2SO4. At the levels of SO2 above 1 percent, no catastrophic corrosion was observed. At these SO2 levels, internal sulfidation appears to be the primary mode of degradation. 40 references.

  15. Charging Properties of Cassiterite (alpha-SnO2) surfaces in NaCl and RbCl Ionic Media.

    SciTech Connect (OSTI)

    Rosenqvist, Jorgen K; Machesky, Michael L.; Vlcek, Lukas; Wesolowski, David J

    2009-09-01

    The acid-base properties of cassiterite (alpha-SnO2) surfaces at 10-50 degrees C were studied using potentiometric titrations of powder suspensions in aqueous NaCl and RbCl media. The proton sorption isotherms exhibited common intersection points in the pH range of 4.0-4.5 under all conditions, and the magnitude of charging was similar but not identical in NaCl and RbCl. The hydrogen bonding configuration at the oxide-water interface, obtained from classical molecular dynamics (MD) simulations, was analyzed in detail, and the results were explicitly incorporated in calculations of protonation constants for the reactive surface sites using the revised MUSIC model. The calculations indicated that the terminal SnOH2 group is more acidic than the bridging Sn2OH group, with protonation constants (log KH) of 3.60 and 5.13 at 25 degrees C, respectively. This is contrary to the situation on the isostructural alpha-TiO2 (rutile), apparently because of the difference in electronegativity between Ti and Sn. MD simulations and speciation calculations indicated considerable differences in the speciation of Na+ and Rb+, despite the similarities in overall charging. Adsorbed sodium ions are almost exclusively found in bidentate surface complexes, whereas adsorbed rubidium ions form comparable numbers of bidentate and tetradentate complexes. Also, the distribution of adsorbed Na+ between the different complexes shows a considerable dependence on the surface charge density (pH), whereas the distribution of adsorbed Rb+ is almost independent of pH. A surface complexation model (SCM) capable of accurately describing both the measured surface charge and the MD-predicted speciation of adsorbed Na+/Rb+ was formulated. According to the SCM, the deprotonated terminal group (SnOH(-0.40)) and the protonated bridging group (Sn2OH+0.36) dominate the surface speciation over the entire pH range of this study (2.7-10). The complexation of medium cations increases significantly with increasing negative surface charge, and at pH 10, roughly 40% of the terminal sites are predicted to form cation complexes, whereas anion complexation is minor throughout the studied pH range.

  16. Site-Specific Imaging of Elemental Steps in Dehydration of Diols on TiO2(110)

    SciTech Connect (OSTI)

    Acharya, Danda P.; Yoon, Yeohoon; Li, Zhenjun; Zhang, Zhenrong; Lin, Xiao; Mu, Rentao; Chen, Long; Kay, Bruce D.; Rousseau, Roger J.; Dohnalek, Zdenek

    2013-11-26

    The conversion of diols on partially reduced TiO2(110) at low coverage was studied using variable-temperature scanning tunneling microscopy, temperature programmed desorption and density functional theory calculations. We find, that below ~230 K, ethane-1,2-diol and propane-1,3-diol molecules adsorb predominantly on five-fold coordinated Ti5c atoms. The dynamic equilibrium between molecularly bound and dissociated species resulting from O-H bond scission and reformation is observed. As the diols start to diffuse on the Ti5c rows above ~230 K, they dissociate irreversibly upon encountering bridging oxygen (Ob) vacancy (VO’s) defects. Two dissociation pathways, one via O-H and the other via C-O bond scission leading to identical surface intermediates, hydroxyalkoxy, Ob-(CH2)n-OH (n = 2, 3) and bridging hydroxyl, HOb, are seen. For O-H bond scission, the Ob-(CH2)n-OH is found on the position of the original VO, while for C-O scission it is found on the adjacent Ob site. Theoretical calculations suggest that the observed mixture of C-O/O-H bond breaking processes are a result of the steric factors enforced upon the diols by the second OH group that is bound to a Ti5c site. At room temperature, rich dissociation/reformation dynamics of the second, Ti5c-bound O-H leads to the formation of dioxo, Ob-(CH2)n-OTi, species. Above ~400 K, both Ob-(CH2)n-OH and Ob-(CH2)n-OTi species convert into a new intermediate, that is centered on Ob row. Combined experimental and theoretical evidence shows that this intermediate is most likely a new dioxo, Ob-(CH2)2-Ob, species. Further annealing leads to sequential C-Ob bond cleavage and alkene desorption above ~ 500 K. Simulations find that the sequential C-O bond breaking process follows a homolytic diradical pathway with the first C-O bond breaking event accompanied by a non-adiabatic electron transfer within the TiO2(110) substrate.

  17. Towards a better understanding on agglomeration mechanisms and thermodynamic properties of TiO2 nanoparticles interacting with natural organic matter

    E-Print Network [OSTI]

    Loosli, Frédéric; Berret, Jean-François; Stoll, Serge

    2015-01-01

    Interaction between engineered nanoparticles and natural organic matter is investigated by measuring the exchanged heat during binding process with isothermal titration calorimetry. TiO2 anatase nanoparticles and alginate are used as engineered nanoparticles and natural organic matter to get an insight into the thermodynamic association properties and mechanisms of adsorption and agglomeration. Changes of enthalpy, entropy and total free energy, reaction stoichiometry and affinity binding constant are determined or calculated at a pH value where the TiO2 nanoparticles surface charge is positive and the alginate exhibits a negative structural charge. Our results indicate that strong TiO2-alginate interactions are essentially entropy driven and enthalpically favorable with exothermic binding reactions. The reaction stoichiometry and entropy gain are also found dependent on the mixing order. Finally correlation is established between the binding enthalpy, the reaction stoichiometry and the zeta potential values ...

  18. Statistical mechanical models for dissociative adsorption of O2 on metal(100) surfaces with blocking, steering, and funneling

    SciTech Connect (OSTI)

    Evans, James W. [Ames Laboratory; Liu, Da-Jiang [Ames Laboratory

    2014-05-20

    We develop statistical mechanical models amenable to analytic treatment for the dissociative adsorption of O2 at hollow sites on fcc(100) metal surfaces. The models incorporate exclusion of nearest-neighbor pairs of adsorbed O. However, corresponding simple site-blocking models, where adsorption requires a large ensemble of available sites, exhibit an anomalously fast initial decrease in sticking. Thus, in addition to blocking, our models also incorporate more facile adsorption via orientational steering and funneling dynamics (features supported by ab initio Molecular Dynamics studies). Behavior for equilibrated adlayers is distinct from those with finite adspecies mobility. We focus on the low-temperature limited-mobility regime where analysis of the associated master equations readily produces exact results for both short- and long-time behavior. Kinetic Monte Carlo simulation is also utilized to provide a more complete picture of behavior. These models capture both the initial decrease and the saturation of the experimentally observed sticking versus coverage, as well as features of non-equilibrium adlayer ordering as assessed by surface-sensitive diffraction.

  19. Ag Out-surface Diffusion In Crystalline SiC With An Effective SiO2 Diffusion Barrier

    SciTech Connect (OSTI)

    Xue, H.; Xiao, Haiyan Y.; Zhu, Zihua; Shutthanandan, V.; Snead, Lance L.; Boatner, Lynn A.; Weber, William J.; Zhang, Y.

    2015-09-01

    For applications of tristructural isotropic (TRISO) fuel particles in high temperature reactors, release of radioactive Ag isotope (110mAg) through the SiC coating layer is a safety concern. To understand the diffusion mechanism, Ag ion implantations near the surface and in the bulk were performed by utilizing different ion energies and energy-degrader foils. High temperature annealing was carried out on the as-irradiated samples to study the possible out-surface diffusion. Before and after annealing, Rutherford backscattering spectrometry (RBS) and secondary ion mass spectrometry (SIMS) measurements were employed to obtain the elemental profiles of the implanted samples. The results suggest little migration of buried Ag in the bulk, and an out-diffusion of the implanted Ag in the near-surface region of single crystal SiC. It is also found that a SiO2 layer, which was formed during annealing, may serve as an effective barrier to reduce or prevent Ag out diffusion through the SiC coating layer.

  20. Multishell Au/Ag/SiO2 nanorods with tunable optical properties as single particle orientation and rotational tracking probes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chen, Kuangcai; Lin, Chia -Cheng; Vela, Javier; Fang, Ning

    2015-04-07

    In this study, three-layer core–shell plasmonic nanorods (Au/Ag/SiO2–NRs), consisting of a gold nanorod core, a thin silver shell, and a thin silica layer, were synthesized and used as optical imaging probes under a differential interference contrast microscope for single particle orientation and rotational tracking. The localized surface plasmon resonance modes were enhanced upon the addition of the silver shell, and the anisotropic optical properties of gold nanorods were maintained. The silica coating enables surface functionalization with silane coupling agents and provides enhanced stability and biocompatibility. Taking advantage of the longitudinal LSPR enhancement, the orientation and rotational information of the hybridmore »nanorods on synthetic lipid bilayers and on live cell membranes were obtained with millisecond temporal resolution using a scientific complementary metal-oxide-semiconductor camera. The results demonstrate that the as-synthesized hybrid nanorods are promising imaging probes with improved sensitivity and good biocompatibility for single plasmonic particle tracking experiments in biological systems.« less

  1. Improving the photocatalytic reduction of CO2 to CO through immobilization of a molecular Re catalyst on TiO2

    E-Print Network [OSTI]

    Windle, Christopher D.; Pastor, Ernest; Reynal, Anna; Whitwood, Adrian C.; Vaynzof, Yana; Durrant, James R.; Perutz, Robin N.; Reisner, Erwin

    2015-01-29

    .K. [+] Current address: School of Chemistry, Newcastle University Newcastle Upon Tyne, NE1 7RU (U.K.) [++] Current address: Centre for Advanced Materials, Heidelberg University Im Neuenheimer Feld 227, 69120 Heidelberg (Germany) Supporting information... solution with TiO2 (5 mg) for 1 h and centrifugation of the RePpic-loaded TiO2 NPs (see the Sup- porting Information, Figure S9). ReP was loaded in water due to the insolubility of RePpic in most common organic solvents and to avoid adsorption of a carbon...

  2. Tailoring single-cycle electromagnetic pulses in the 2-9 THz frequency range using DAST/SiO2 multilayer structures pumped at Ti:sapphire wavelength

    E-Print Network [OSTI]

    Stepanov, Andrei G; Bonacina, Luigi; Wolf, Jean-Pierre; Hauri, Christoph P

    2014-01-01

    We present a numerical parametric study of single-cycle electromagnetic pulse generation in a DAST/SiO2 multilayer structure via collinear optical rectification of 800 nm femtosecond laser pulses. It is shown that modifications of the thicknesses of the DAST and SiO2 layers allow tuning of the average frequency of the generated THz pulses in the frequency range from 3 to 6 THz. The laser-to-THz energy conversion efficiency in the proposed structures is compared with that in a bulk DAST crystal and a quasi-phase-matching periodically poled DAST crystal and shows significant enhancement.

  3. Effects of Dye Loading Conditions on the Energy Conversion Efficiency of ZnO and TiO2 Dye-Sensitized Solar Cells

    E-Print Network [OSTI]

    Cao, Guozhong

    light conversion efficiency of zinc oxide (ZnO) film electrodes in dye-sensitized solar cellsEffects of Dye Loading Conditions on the Energy Conversion Efficiency of ZnO and TiO2 Dye-Sensitized Solar Cells Tammy P. Chou, Qifeng Zhang, and Guozhong Cao* Materials Science and Engineering, Uni

  4. Facile and Green Preparation for the Formation of MoO2GO Composites as Anode Material for Lithium-Ion Batteries

    E-Print Network [OSTI]

    Cao, Guozhong

    as an anode material for lithium-ion batteries, the MoO2-GO composites exhibited an improved storage capacity for lithium-ion batteries. 1. INTRODUCTION With the fast-growing demand on petroleum resources and gaseous cycling life, and environmental benignity, lithium- ion batteries (LIBs) have been regarded as one

  5. PHYSICAL REVIEW B 86, 144109 (2012) Intrinsic point-defect equilibria in tetragonal ZrO2: Density functional theory analysis

    E-Print Network [OSTI]

    Yildiz, Bilge

    2012-01-01

    on the technologically important tetragonal zirconium oxide, T-ZrO2. We showed that phonon free energy and electronic) belongs to the list of the most important metal oxides due to its wide usage in different technological for Electrochemical Interfaces, Department of Nuclear Science and Engineering, Massachusetts Institute of Technology

  6. Impact of three different TiO2 morphologies on hydrogen evolution by methonal assisted water-splitting: nanoparticles, nanotubes and

    E-Print Network [OSTI]

    Boyer, Edmond

    -splitting: nanoparticles, nanotubes and aerogels. (published in International Journal of Hydrogen Energy 36, 22 (2011, nanotubes and aerogels. These materials have shown different behaviours depending on both their composition of the samples (nanotubes or aerogels). Among all the tested samples, the TiO2 aerogel supported Pt one exhibited

  7. Charge transfer from TiO2 into adsorbed benzene diazonium compounds Tel-Aviv University, School of Electrical Engineering, Ramat-Aviv 69978, Israel

    E-Print Network [OSTI]

    Shapira, Yoram

    Charge transfer from TiO2 into adsorbed benzene diazonium compounds A. Merson Tel-Aviv University benzene diazonium compounds has been investigated using cyclic voltammetry, x-ray photoelectron that the potential of maximum electron transfer depends strongly on the dipole moment of the benzene compound. Two

  8. Preparation and Comparison of Supported Gold Nanocatalysts on Anatase, Brookite, Rutile, and P25 Polymorphs of TiO2 for Catalytic Oxidation of CO

    E-Print Network [OSTI]

    Pennycook, Steve

    Polymorphs of TiO2 for Catalytic Oxidation of CO Wenfu Yan, Bei Chen, S. M. Mahurin, V. Schwartz, D. R to an identical sequence of treatment and measurements of catalytic CO oxidation activity. The as on selected metal oxides exhibit surprisingly high catalytic activity for CO oxidation even at 200 K.6,7 Now

  9. Role of ethylene on surface oxidation of TiO2(110) Y. Murata, V. Petrova, I. Petrov, C. V. Ciobanu, and S. Kodambaka

    E-Print Network [OSTI]

    Ciobanu, Cristian

    ,6 and photo-assisted purification of volatile organic compounds (VOCs),7 as a support for metal catalysts,8 all of the above-mentioned applications, TiO2 is well-known for its photo-assisted oxidation of VOCs understanding of the factors controlling the surface stoichiometry is critical for rational design of high

  10. Ti-substituted tunnel-type Na0.44MnO2 oxide as a negative electrode for aqueous sodium-ion batteries

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wang, Yuesheng; Liu, Jue; Lee, Byungju; Qiao, Ruimin; Yang, Zhenzhong; Xu, Shuyin; Yu, Xiqian; Gu, Lin; Hu, Yong-Sheng; Yang, Wanli; et al

    2015-03-25

    The aqueous sodium-ion battery system is a safe and low-cost solution for large-scale energy storage, due to the abundance of sodium and inexpensive aqueous electrolytes. Although several positive electrode materials, e.g., Na0.44MnO2, were proposed, few negative electrode materials, e.g., activated carbon and NaTi2(PO4)3, are available. Here we show that Ti-substituted Na0.44MnO2 (Na0.44[Mn1-xTix]O2) with tunnel structure can be used as a negative electrode material for aqueous sodium-ion batteries. This material exhibits superior cyclability even without the special treatment of oxygen removal from the aqueous solution. Atomic-scale characterizations based on spherical aberration-corrected electron microscopy and ab initio calculations are utilized to accuratelymore »identify the Ti substitution sites and sodium storage mechanism. Ti substitution tunes the charge ordering property and reaction pathway, significantly smoothing the discharge/charge profiles and lowering the storage voltage. Both the fundamental understanding and practical demonstrations suggest that Na0.44[Mn1-xTix]O2 is a promising negative electrode material for aqueous sodium-ion batteries.« less

  11. Spectroscopy of the transition state: Elementary reactions of the hydroxyl radical studied by photoelectron spectroscopy of O (H2O) and H3O2

    E-Print Network [OSTI]

    Neumark, Daniel M.

    Spectroscopy of the transition state: Elementary reactions of the hydroxyl radical studied to study the unstable neutral complexes involved in two fundamental re- actions of the hydroxyl radical OH H2OH2O OH, 1 OH OHO 3 P H2O. 2 The role of the hydroxyl radical as a propagator of chain reactions

  12. Ti-substituted tunnel-type Na0.44MnO2 oxide as a negative electrode for aqueous sodium-ion batteries

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wang, Yuesheng [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP); Liu, Jue [Brookhaven National Lab. (BNL), Upton, NY (United States); Lee, Byungju [Seoul National Univ. (Korea, Republic of); Qiao, Ruimin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source; Yang, Zhenzhong [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP); Xu, Shuyin [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP); Yu, Xiqian [Brookhaven National Lab. (BNL), Upton, NY (United States)] (ORCID:000000018513518X); Gu, Lin [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP); Hu, Yong-Sheng [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP)] (ORCID:0000000284306474); Yang, Wanli [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source] (ORCID:0000000306668063); Kang, Kisuk [Seoul National Univ. (Korea, Republic of); Li, Hong [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP)] (ORCID:000000028659086X); Yang, Xiao-Qing [Brookhaven National Lab. (BNL), Upton, NY (United States); Chen, Liquan [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP); Huang, Xuejie [Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics (IHEP)

    2015-03-25

    The aqueous sodium-ion battery system is a safe and low-cost solution for large-scale energy storage, due to the abundance of sodium and inexpensive aqueous electrolytes. Although several positive electrode materials, e.g., Na0.44MnO2, were proposed, few negative electrode materials, e.g., activated carbon and NaTi2(PO4)3, are available. Here we show that Ti-substituted Na0.44MnO2 (Na0.44[Mn1-xTix]O2) with tunnel structure can be used as a negative electrode material for aqueous sodium-ion batteries. This material exhibits superior cyclability even without the special treatment of oxygen removal from the aqueous solution. Atomic-scale characterizations based on spherical aberration-corrected electron microscopy and ab initio calculations are utilized to accurately identify the Ti substitution sites and sodium storage mechanism. Ti substitution tunes the charge ordering property and reaction pathway, significantly smoothing the discharge/charge profiles and lowering the storage voltage. Both the fundamental understanding and practical demonstrations suggest that Na0.44[Mn1-xTix]O2 is a promising negative electrode material for aqueous sodium-ion batteries.

  13. Surface characterization studies of TiO2 supported manganese oxide catalysts for low temperature SCR of NO with NH3

    E-Print Network [OSTI]

    Boolchand, Punit

    power plant conditions using GHSV = 50,000 hÀ1 was studied. The catalyst with 16.7 wt.% Mn/TiO2 anatase gas. This is because the catalyst has high SCR activity and is resistant to SO2 poisoning of the desulfurization and particulate control devices immediately after the steam generator in order to avoid spending

  14. Formation of single-domain anatase TiO2,,001...-,,14... islands on SrTiO3,,001... after thermal annealing

    E-Print Network [OSTI]

    Castell, Martin

    studied as a promising material for applications in sensors, photocataly- sis, solar energy conversion annealing Fabien Sillya) and Martin R. Castellb) Department of Materials, University of Oxford, Parks Road these materials are strongly dependent on the nature of the TiO2 surfaces and its nano- structures

  15. An experimental and theoretical investigation of the structure and reactivity of bilayered VOx/TiOx/SiO2 catalysts for methanol oxidation

    E-Print Network [OSTI]

    Bell, Alexis

    /TiOx/SiO2 catalysts for methanol oxidation William C. Vining, Anthony Goodrow, Jennifer Strunk, Alexis T Accepted 22 December 2009 Available online 2 February 2010 Keywords: Vanadia Silica Titania Methanol vanadia surface density (0.7 V/nm2 ), the turnover frequency for methanol oxidation to formaldehyde

  16. Structural and electronic properties of cubic HfO2 surfaces G.H. Chen, Z.F. Hou, X.G. Gong *

    E-Print Network [OSTI]

    Gong, Xingao

    Structural and electronic properties of cubic HfO2 surfaces G.H. Chen, Z.F. Hou, X.G. Gong@fudan.edu.cn (X.G. Gong). www.elsevier.com/locate/commatsci Available online at www

  17. Mechanistic Aspects and Reaction Pathways for Oxidative Coupling of Methane on Mn/Na2WO4/SiO2 Catalysts

    E-Print Network [OSTI]

    Iglesia, Enrique

    sensitivity to the energy of the C-H bond containing the hydrogen abstracted. These coupled homogeneous-catalytic+ selectivities but only when OH radicals are maintained at equilibrium concentrations via catalytic H2O-O2 required in indirect routes involving CH4 reforming and Fischer­Tropsch synthesis,3 while producing light

  18. Enhanced Performance of CdS/CdSe Quantum Dot Cosensitized Solar Cells via Homogeneous Distribution of Quantum Dots in TiO2

    E-Print Network [OSTI]

    Cao, Guozhong

    , simply increasing film thickness did not make significant contribution to improving solar cell efficiencyEnhanced Performance of CdS/CdSe Quantum Dot Cosensitized Solar Cells via Homogeneous Distribution cosensitized solar cells. The CdS and CdSe quantum dots were prepared on TiO2 mesoporous film through

  19. The effect of chemical residues on the physical and electrical properties of chemical vapor deposited graphene transferred to SiO2

    E-Print Network [OSTI]

    is etched away.10 Removal of PMMA from graphene is problematic. Conventional semiconductor surface cleaning deposited graphene transferred to SiO2 A. Pirkle,1 J. Chan,1 A. Venugopal,2 D. Hinojos,1 C. W. Magnuson,3 S) The effects of residues introduced during the transfer of chemical vapor deposited graphene from a Cu

  20. Witten's Problems, Set Six ---N o . 2 (solution written by D. Freed) (2) In this exercise we will compute the oneloop renormalization of U(1) gauge theory

    E-Print Network [OSTI]

    Witten's Problems, Set Six --- N o . 2 (solution written by D. Freed) Problem: (2) In this exercise is D ij = D 0 ij + \\Sigma ij , where \\Sigma ij , the ``self­energy,'' is to be computed from loops. A very fundamental property of \\Sigma ij is that in momentum space k i \\Sigma ij (k) = 0. (An explanation

  1. This study focuses on the methodology of generating and measuring HONO to study its potential formation from self-cleaning surfaces such as TiO2.

    E-Print Network [OSTI]

    Collins, Gary S.

    Vehicle emissions, when oxidized in the presence of NOx and sunlight, produce photochemical air pollution as a photocatalyst to oxidize surface absorbed compounds. It has been proposed that air pollution can be reduced pollution by increasing the formation arte of HO radical. The oxidation of VOCs by TiO2 can lead

  2. Magnetic Fe3O4@TiO2 Nanoparticles-based Test Strip Immunosensing Device for Rapid Detection of Phosphorylated Butyrylcholinesterase

    SciTech Connect (OSTI)

    Ge, Xiaoxiao; Zhang, Weiying; Lin, Yuehe; Du, Dan

    2013-12-15

    An integrated magnetic nanoparticles-based test-strip immunosensing device was developed for rapid and sensitive quantification of phosphorylated butyrylcholinesterase (BChE), the biomarker of exposure to organophosphous pesticides (OP), in human plasma. In order to overcome the difficulty in scarce availability of OP-specific antibody, here magnetic Fe3O4@TiO2 nanoparticles were used and adsorbed on the test strip through a small magnet inserted in the device to capture target OP-BChE through selective binding between TiO2 and OP moiety. Further recognition was completed by horseradish peroxidase (HRP) and anti-BChE antibody (Ab) co-immobilized gold nanoparticles (GNPs). Their strong affinities among Fe3O4@TiO2, OP-BChE and HRP/Ab-GNPs were characterized by quartz crystal microbalance (QCM), surface plasmon resonance (SPR) and square wave voltammetry (SWV) measurements. After cutting off from test strip, the resulted immunocomplex (HRP/Ab-GNPs/OP-BChE/Fe3O4@TiO2) was measured by SWV using a screen printed electrode under the test zone. Greatly enhanced sensitivity was achieved by introduction of GNPs to link enzyme and antibody at high ratio, which amplifies electrocatalytic signal significantly. Moreover, the use of test strip for fast immunoreactions reduces analytical time remarkably. Coupling with a portable electrochemical detector, the integrated device with advanced nanotechnology displays great promise for sensitive, rapid and in-filed on-site evaluation of OP poisoning.

  3. Model relation between the energy-band edge and the Fermi level of the nondegenerate semiconductor TiO2: Application to electrochemistry

    E-Print Network [OSTI]

    Li, Weixue

    , is demonstrated in the comparative studies of anatase and rutile TiO2 that are used in photocatalysis and dye, photocatalysis, and photovoltaics.9,10 For example, the standard relations between EF and EC/EV based on rigid, i.e., anatase and rutile, are widely used in photocatalysis and dye-sensitized solar cell DSSC

  4. Stress Relaxation of Compression Loaded Plasma-Sprayed 7 Wt% Y2O3ZrO2 Stand-Alone Coatings

    E-Print Network [OSTI]

    Trice, Rodney W.

    -temperature environments such as gas-turbine engines.1­4 TBCs typically consist of a metallic substrate coated with an B100Stress Relaxation of Compression Loaded Plasma-Sprayed 7 Wt% Y2O3­ZrO2 Stand-Alone Coatings Graeme R. Dickinson, Chris Petorak, Keith Bowman, and Rodney W. Tricew School of Materials Engineering

  5. Detailed scanning probe microscopy tip models determined from simultaneous atom-resolved AFM and STM studies of the TiO2(110) surface

    E-Print Network [OSTI]

    Kühnle, Angelika

    scattering theory, we demonstrate how the state of the scanning probe microscopy SPM tip in the experiments may be determined. The analysis of a large number of experimental SPM images recorded with different-AFM and the tunneling current It images on TiO2 110 surface. The exact state of the SPM tip must, therefore

  6. Heterostructured Ceramic Powders for Photocatalytic Hydrogen Production: Nanostructured TiO2 Shells Surrounding Microcrystalline (Ba,Sr)TiO3 Cores

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    Heterostructured Ceramic Powders for Photocatalytic Hydrogen Production: Nanostructured TiO2 Shells areas, but had the highest rates of photochemical hydrogen production from water/methanol solu- tions coatings. I. Introduction INTEREST in photochemical hydrogen production began sev- eral decades ago upon

  7. Effect of the Presence of Iodide on the Electron Injection Dynamics of Dye-Sensitized TiO2-Based Solar Cells

    E-Print Network [OSTI]

    McCusker, James K.

    Solar Cells Amanda L. Smeigh, Jordan E. Katz, Bruce S. Brunschwig,*,,§ Nathan S. Lewis,*, and James K dynamics of dye-sensitized TiO2-based solar cells have been investigated to determine the effects -/I- were fully functional solar cells whose steady-state photocurrents were directly measured. In (n

  8. PHYSICAL REVIEW B 85, 155202 (2012) Structural, electronic, and hyperfine properties of pure and Ta-doped m-ZrO2

    E-Print Network [OSTI]

    Svane, Axel Torstein

    2012-01-01

    , in refractory materials, solid oxide fuel cell electrolytes, catalyst substrates, protective coatings Zirconium dioxide (zirconia) is one of the most important compounds in materials science and technology and (sometimes) with the addition of small amounts of impurities, ZrO2 has applications, for example

  9. High Catalytic Activity of Au/CeOx/TiO2(110) Controlled by the Nature of the Mixed Metal Oxide at the Nanometer Level

    SciTech Connect (OSTI)

    Park, J.; Graciani, J; Evans, J; Stacchiola, D; Ma, S; Liu, P; Nambu, A; Sanz, J; Hrbek, J; et. al.

    2009-01-01

    Mixed-metal oxides play a very important role in many areas of chemistry, physics, materials science, and geochemistry. Recently, there has been a strong interest in understanding phenomena associated with the deposition of oxide nanoparticles on the surface of a second (host) oxide. Here, scanning tunneling microscopy, photoemission, and density-functional calculations are used to study the behavior of ceria nanoparticles deposited on a TiO2(110) surface. The titania substrate imposes nontypical coordination modes on the ceria nanoparticles. In the CeOx/TiO2(110) systems, the Ce cations adopt an structural geometry and an oxidation state (+3) that are quite different from those seen in bulk ceria or for ceria nanoparticles deposited on metal substrates. The increase in the stability of the Ce3+ oxidation state leads to an enhancement in the chemical and catalytic activity of the ceria nanoparticles. The codeposition of ceria and gold nanoparticles on a TiO2(110) substrate generates catalysts with an extremely high activity for the production of hydrogen through the water-gas shift reaction (H2O + CO ? H2 + CO2) or for the oxidation of carbon monoxide (2CO + O2 ? 2CO2). The enhanced stability of the Ce3+ state is an example of structural promotion in catalysis described here on the atomic level. The exploration of mixed-metal oxides at the nanometer level may open avenues for optimizing catalysts through stabilization of unconventional surface structures with special chemical activity.

  10. Conversion of CH4 into H2 at 300 C using Pd/MnO2 catalyst made with an effect of water oxidation

    SciTech Connect (OSTI)

    Koyanaka, Hideki; Takeuchi, K; Kolesnikov, Alexander I

    2014-01-01

    A novel electricity-free deposition of palladium on the surface of manganese dioxide, which has a crystal structure of ramsdellite, was studied. Using the Pd deposition, a nano-particle of Pd/MnO2 was prepared, and it was used for a catalytic performance for reforming methane into hydrogen at 300 C.

  11. The OH-Initiated Oxidation of 1,3-Butadiene in the Presence of O2 and NO: A Photolytic Route To Study Isomeric Selective Reactivity

    E-Print Network [OSTI]

    North, Simon W.

    The OH-Initiated Oxidation of 1,3-Butadiene in the Presence of O2 and NO: A Photolytic Route, 2005 We report the study of the isomeric selective OH-initiated oxidation of 1,3-butadiene provides only one of the possible OD-butadiene adducts, the minor addition channel product, simplifying

  12. Dual Phase Li4 Ti5O12–TiO2 Nanowire Arrays As Integrated Anodes For High-rate Lithium-ion Batteries

    SciTech Connect (OSTI)

    Liao, Jin; Chabot, Victor; Gu, Meng; Wang, Chong M.; Xiao, Xingcheng; Chen, Zhongwei

    2014-08-19

    Lithium titanate (Li4Ti5O12) is well known as a zero strain material inherently, which provides excellent long cycle stability as a negative electrode for lithium ion batteries. However, the low specific capacity (175 mA h g?1) limits it to power batteries although the low electrical conductivity is another intrinsic issue need to be solved. In this work, we developed a facile hydrothermal and ion-exchange route to synthesize the self-supported dual-phase Li4Ti5O12–TiO2 nanowire arrays to further improve its capacity as well as rate capability. The ratio of Li4Ti5O12 to TiO2 in the dual phase Li4Ti5O12–TiO2 nanowire is around 2:1. The introduction of TiO2 into Li4Ti5O12 increases the specific capacity. More importantly, by interface design, it creates a dual-phase nanostructure with high grain boundary density that facilitates both electron and Li ion transport. Compared with phase-pure nanowire Li4Ti5O12 and TiO2 nanaowire arrays, the dual-phase nanowire electrode yielded superior rate capability (135.5 at 5 C, 129.4 at 10 C, 120.2 at 20 C and 115.5 mA h g?1 at 30 C). In-situ transmission electron microscope clearly shows the near zero deformation of the dual phase structure, which explains its excellent cycle stability.

  13. Ab initio molecular dynamics simulations of properties of a-Al2O3 /vacuum and a-ZrO2 /vacuum vs a-Al2O3/Ge,,100...,,21...

    E-Print Network [OSTI]

    Kummel, Andrew C.

    -Al2O3/Ge,,100...,,2Ã1... and a-ZrO2/Ge,,100...,,2Ã1... interfaces Evgueni A. Chagarova and Andrew C The local atomic structural properties of a-Al2O3, a-ZrO2 vacuum/oxide surfaces, and a-Al2O3/Ge 100 2 1 , a-ZrO2/Ge 100 2 1 oxide/semiconductor interfaces were investigated by density-functional theory DFT

  14. Nanostructure and infrared photoluminescence of nanocrystalline Ge formed by reduction of Si0.75Ge0.25O2 Si0.75Ge0.25 using various H2 pressures

    E-Print Network [OSTI]

    Nanostructure and infrared photoluminescence of nanocrystalline Ge formed by reduction of Si0.75Ge0.25O2 ÕSi0.75Ge0.25 using various H2 pressures Gianni Taraschi,a) Sajan Saini, Wendy W. Fan, Lionel C Ge in SiO2 was synthesized by the reduction of Si0.75Ge0.25O2 with H2 , at various annealing

  15. Evidence for energy coupling from the SiD vibration mode to the SiSi and SiO vibration modes at the SiO2 Si interface

    E-Print Network [OSTI]

    Chen, Zhi

    at the SiO2 ÕSi interface Zhi Chen,a) Jun Guo, and Pangleen Ong Department of Electrical and Computer

  16. Fabrication of CeO2 by sol-gel process based on microfluidic technology as an analog preparation of ceramic nuclear fuel microspheres

    E-Print Network [OSTI]

    Ye, Bin; Li, Jiaolong; Zhao, Zichen; Chang, Zhenqi; Serra, Christophe A

    2012-01-01

    Microfluidics integrated with sol-gel processes is introduced in preparing monodispersed MOX nuclear fuel microspheres using nonactive cerium as a surrogate for uranium or plutonium. The detailed information about microfluidic devices and sol-gel processes are provided. The effects of viscosity and flow rate of continuous and dispersed phase on size and size distribution of CeO2 microspheres have been investigated. A comprehensive characterization of the CeO2 microspheres has been conducted, including XRD pattern, SEM, density, size and size distribution. The size of prepared monodisperse particles can be controlled precisely in range of 10{\\mu}m to 1000{\\mu}m and the particle CV is below 3%.

  17. Fabrication of CeO2 by sol-gel process based on microfluidic technology as an analog preparation of ceramic nuclear fuel microspheres

    E-Print Network [OSTI]

    Bin Ye; Jilang Miao; Jiaolong Li; Zichen Zhao; Zhenqi Chang; Christophe A. Serra

    2012-12-15

    Microfluidics integrated with sol-gel processes is introduced in preparing monodispersed MOX nuclear fuel microspheres using nonactive cerium as a surrogate for uranium or plutonium. The detailed information about microfluidic devices and sol-gel processes are provided. The effects of viscosity and flow rate of continuous and dispersed phase on size and size distribution of CeO2 microspheres have been investigated. A comprehensive characterization of the CeO2 microspheres has been conducted, including XRD pattern, SEM, density, size and size distribution. The size of prepared monodisperse particles can be controlled precisely in range of 10{\\mu}m to 1000{\\mu}m and the particle CV is below 3%.

  18. Syngas production from butane using a flame-made Rh/Ce0.5Zr0.5O2 Nico Hotz a

    E-Print Network [OSTI]

    Daraio, Chiara

    Syngas production from butane using a flame-made Rh/Ce0.5Zr0.5O2 catalyst Nico Hotz a , Michael J the production of H2- and CO-rich syngas from butane was investigated for different Rh loadings (0­2.0 wt% Rh for a temperature range from 225 to 750 8C. The main goal of this study was the efficient processing of butane

  19. Preparation, characterization of Fe3O4 at TiO2 magnetic nanoparticles and their application for immunoassay of biomarker of exposure to organophosphorus pesticides

    SciTech Connect (OSTI)

    Zhang, Xiao; Wang, Hongbo; Yang, Chunming; Du, Dan; Lin, Yuehe

    2013-03-15

    Novel Fe3O4 at TiO2 magnetic nanoparticles were prepared and developed for a new nanoparticle-based immunosensor for electrochemical quantification of organophosphorylated butyrylcholinesterase (BChE) in plasma, a specific biomarker of exposure to organophosphorus (OP) agents. The Fe3O4 at TiO2 nanoparticles were synthesized by hydrolysis of tetrabutyltitanate on the surface of Fe3O4 magnetic nanospheres, and characterized by attenuated total reflection Fourier-transform infrared spectra, transmission electron microscope and X-ray diffraction. The functional Fe3O4 at TiO2 nanoparticles were performed as capture antibody to selectively enrich phosphorylated moiety instead of phosphoserine antibody in the traditional sandwich immunoassays. The secondary recognition was served by quantum dots (QDs)-tagged anti-BChE antibody (QDs-anti-BChE). With the help of a magnet, the resulting sandwich-like complex, Fe3O4 at TiO2/OP-BChE/QDs-anti-BChE, was easily isolated from sample solutions and the released cadmium ions were detected on a disposable screen-printed electrode (SPE). The binding affinities were investigated by both surface plasmon resonance (SPR) and square wave voltammetry (SWV). This method not only avoids the drawback of unavailability of commercial OP-specific antibody but also amplifies detection signal by QDs-tags together with easy separation of samples by magnetic forces. The proposed immunosensor yields a linear response over a broad OP-BChE concentrations range from 0.02 to 10 nM, with detection limit of 0.01 nM. Moreover, the disposable nanoparticle-based immunosensor has been validated with human plasma samples. It offers a new method for rapid, sensitive, selective and inexpensive screening/evaluating exposure to OP pesticides.

  20. Catalytic epoxidation of propene with H2OO2 reactants on Au/TiO2w Manuel Ojeda and Enrique Iglesia*

    E-Print Network [OSTI]

    Iglesia, Enrique

    converts, however, to H2O via unproductive side reactions, and leads to low H2 utilization efficiencies (30­40%, defined as PO formed per H2 consumed) and unfavorable economics.2 H2O2 was recently detected during COO3, Alcoa) was treated in air at 923 K for 5 h and suspended in deionized H2O (120 cm3 ) at 353 K

  1. Impact of Solvent on Photocatalytic Mechanisms: Reactions of Photodesorption Products with Ice Overlayers on the TiO2(110) Surface

    SciTech Connect (OSTI)

    Shen, Mingmin; Henderson, Michael A.

    2011-04-07

    The effects of water and methanol ice overlayers on the photodecomposition of acetone on rutile TiO2(110) were evaluated in ultrahigh vacuum (UHV) using photon stimulated desorption (PSD) and temperature programmed desorption (TPD). In the absence of ice overlayers, acetone photodecomposed on TiO2(110) at 95 K by ejection of a methyl radical into the gas phase and formation of acetate on the surface. With ice overlayers, the methyl radicals are trapped at the interface between TiO2(110) and the ice. When water ice was present, these trapped methyl radicals reacted either with each other to form ethane or with other molecules in the ice (e.g., water or displaced acetone) to form methane (CH4), ethane (CH3CH3) and other products (e.g., methanol), with all of these products trapped in the ice. The new products were free to revisit the surface or depart during desorption of the ice. When methanol ice was present, methane formation came about only from reaction of trapped methyl radicals with the methanol ice. Methane and ethane slowly leaked through methanol ice overlayers into vacuum at 95 K, but not through water ice overlayers. Different degrees of site competition between water and acetone, and between methanol and acetone led to different hydrogen abstraction pathways in the two ices. These results provide new insights into product formation routes and solution-phase radical formation mechanisms that are important in heterogeneous photocatalysis.

  2. Structure-activity relationship of Au-ZrO2 catalyst on formation of hydroxyl groups and its influence on CO oxidation

    SciTech Connect (OSTI)

    Karwacki, Christopher J; Ganesh, Panchapakesan; Kent, P. R. C.; Gordon, Wesley O; Peterson, Gregory W; Niu, Jun Jie; Gogotsi, Yury G.

    2013-01-01

    The effect of changes in morphology and surface hydroxyl species upon thermal treatment of zirconia on the oxidation activity of Au/ZrO2 catalyst was studied. We observed using transmission Fourier transform infrared (FTIR) spectroscopy progressive changes in the presence of monodentate (type I), bidentate (type II) and hydrogen bridged species (type III) for each of the thermally treated (85 to 500 C) supports consisting of bare zirconia and Au/ZrO2 catalysts. Furthermore, structural changes in zirconia were accompanied by an increase in crystal size (7 to 58 nm) and contraction of the supports porosity (SSA 532 to 7 m2 g 1) with increasing thermal treatment. Deposition of gold nanoparticles under similar preparation conditions on different thermally treated zirconia resulted in changes in the mean gold cluster size, ranging from 3.7 to 5.6 nm. Changes in the surface hydroxyl species, support structure and size of the gold centers are important parameters responsible for the observed decrease (>90%) in CO conversion activity for the Au/ZrO2 catalysts. Density functional theory calculations provide evidence of increased CO binding to Au nanoclusters in the presence of surface hydroxyls on zirconia, which increases charge transfer at the perimeter of the gold nanocluster on zirconia support. This further helps in reducing a model CO-oxidation reaction barrier in the presence of surface hydroxyls. This work demonstrates the need to understand the structure activity relationship of both the support and active particles for the design of catalytic materials.

  3. Structure-Activity Relationship of Au/ZrO2 Catalyst on Formation of Hydroxyl Groups and Its Influence on CO Oxidation

    SciTech Connect (OSTI)

    Karwacki, Christopher J; Ganesh, Panchapakesan; Gordon, Wesley O; Peterson, Gregory W; Niu, Jun Jie; Gogotsi, Yury G.

    2013-01-01

    The effect of changes in morphology and surface hydroxyl species upon thermal treatment of zirconia on the oxidation activity of Au/ZrO2 catalyst was studied. We observed using transmission fourier transform infrared (FTIR) spectroscopy progressive changes in the presence of monodentate (type I), bidentate (type II) and hydrogen bridged species (type III) for each of the thermally treated (85 to 500 C) supports consisting of bare zirconia and Au/ZrO2 catalysts. Furthermore, structural changes in zirconia were accompanied by an increase in crystal size (7 to 58 nm) and contraction of the supports porosity (SSA 532 to 7 m2/g) with increasing thermal treatment. Deposition of gold nanoparticles under similar preparation conditions on different thermally treated zirconia resulted in changes in the mean gold cluster size, ranging from 3.7 to 5.6 nm. Changes in the surface hydroxyl species, support structure and size of the gold centers are important parameters responsible for the observed decrease (> 90 %) in CO conversion activity for the Au/ZrO2 catalysts. Density functional theory calculations provide evidence of increased CO binding to Au nanoclusters in the presence of surface hydroxyls on zirconia, which increases charge transfer at the perimeter of the gold nanocluster on zirconia support. This further helps in reducing a model CO-oxidation reaction barrier in the presence of surface hydroxyls. This work demonstrates the need to understand the structure-activity relationship of both the support and active particles for the design of catalytic materials.

  4. Catalyst Activity and Post-operation Analyses of Pt/TiO2 (Rutile) Catalysts Used in the Sulfuric Acid Decomposition Reaction

    SciTech Connect (OSTI)

    Lucia M. Petkovic; Daniel M. Ginosar; Harry W. Rollins; Kyle C. Burch; Patrick J. Pinhero; Helen H. Farrell

    2007-06-01

    Production of hydrogen by splitting of water at lower temperatures than by direct thermal decomposition can be achieved by a series of particular chemical reactions that establish a thermochemical cycle [1]. Among the high number of thermochemical water-splitting cycles proposed in the literature [2], the sulfur-based group is of considerable interest. All the sulfur-based cycles employ the catalytic decomposition of sulfuric acid into SO2 and O2. The produced O2 corresponds to the O2 generated from water in the overall cycle. Research performed at the Idaho National Laboratory [3] has found that even one of the most stables catalysts, Pt supported on low surface area titania, deactivates with time on stream (TOS). To develop an understanding of the factors that cause catalyst deactivation, samples of 1% Pt supported on titania (rutile) catalyst were submitted to flowing concentrated sulfuric acid at 1123 K and atmospheric pressure for different TOSs between 0 and 548 h and a number of chemical and spectroscopic analyses applied to the spent samples.

  5. Ge MOS Characteristics with CVD HfO2 Gate Dielectrics and TaN Gate Electrode W. P. Bai*, N. Lu*, J. Liu*, A. Ramirez**, D. L. Kwong*, D. Wristers**, A. Ritenour#

    E-Print Network [OSTI]

    Ge MOS Characteristics with CVD HfO2 Gate Dielectrics and TaN Gate Electrode W. P. Bai*, N. Lu*, J, we report for the first time Ge MOS characteristics with ultra thin rapid thermal CVD HfO2 gate dielectrics and TaN gate electrode. Using the newly developed pre- gate cleaning and NH3-based Ge surface

  6. LF IOT Cavity Laboratory Experiments Photoconductive Amplifier Collaborative Research on

    E-Print Network [OSTI]

    Anlage, Steven

    /Objectives Develop prototypes of EM sources for mobile, reconfigurable ionospheric heaters based on: ! !! (i geo- magnetic latitudes and diurnal variation and solar cycle;! !! (iii) Understanding of modern high

  7. Applying ICT and IoT to Multifamily Buildings

    Broader source: Energy.gov (indexed) [DOE]

    peak demand costs Utility Approved Revenue Grade Web Accessible Data Install Wireless HVAC Load Control Empower management with 247 control Mobile alerts...

  8. Reducing Configuration Complexity with Next Gen IoT Networks

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested PartiesBuildingBudgetFinancial Opportunities » Pastams AG 2015

  9. Near-resonance enhanced O2 detection for dual-broadband pure rotational coherent anti-Stokes Raman scattering with an ultraviolet-visible setup at 266 nm

    SciTech Connect (OSTI)

    Schenk, Martin; Seeger, Thomas; Leipertz, Alfred

    2005-07-01

    Broadband and dual-broadband coherent anti-Stokes Raman scattering (CARS) are widely established tools for nonintrusive gas diagnostics. Up to now the investigations have been mainly performed for electronic nonresonant conditions of the gas species of interest. We report on the enhancement of the O2-N2 detection limit of dual-broadband pure rotational CARS by shifting the wavelength of the narrowband pump laser from the commonly used 532-266 nm. This enhancement is caused when the Schumann-Runge absorption band is approached near 176 nm. The principal concept of this experiment, i.e., covering the Raman resonance with a single- or dual-broadband combination of lasers in the visible range and moving only the narrowband probe laser near or directly into electronic resonant conditions in the UV range, should also be applicable to broadband CARS experiments to directly exploit electronic resonance effects for the purpose of single-shot concentration measurements of minority species. To quantify the enhancement in O2 sensitivity, comparative measurements at both a 266 and a 532 nm narrowband pump laser wavelength are presented, employing a 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyram (DCM) dye laser as a broadband laser source at 635 nm. An increase of approximately 13% in the ratio of the rotational CARS cross sections of O2 and N2 was obtained. The broad spectral width of the CARS excitation profile was approximately equal for both setups. Further enhancement should be achievable by shifting the narrowband pump laser closer toward 176 nm, for example, with a frequency-doubled optical parametric oscillator or an excimer laser. The principal concept of this experiment should also be applicable to broadband CARS experiments to directly exploit electronic resonance effects of the narrowband pump laser with electronic transitions of minority species for the purpose of single-shot concentration measurements of those species.

  10. Co-operativity among defect sites in AnO2+ and An4O9 (An = U, Np or Pu)

    SciTech Connect (OSTI)

    Andersson, Anders David; Lezama Pacheco, Juan; Uberuaga, Blas P; Conradson, Steven D

    2008-01-01

    Actinide dioxides derived from the AnO{sub 2} fluorite lattice are of high technological relevance due to their application in nuclear reactor fuels. Oxidation of AnO{sub 2} compounds emerges as a central theme in fuel fabrication, reactor operation, long-term storage forms for both spent fuels and surplus weapons materials, and environmental actinide migration. In this paper, we use density functional theory calculations to study the oxidation of uranium, neptunium and plutonium dioxides, AnO{sub 2} (An = U, Np or Pu), in O{sub 2} and O{sub 2}/H{sub 2}O environments. We pay particular attention to the formation of oxygen clusters (co-operativity) in AnO{sub 2+x} and how this phenomenon govern oxidation thermodynamics and the development of ordered An{sub 4}O{sub 9} compounds. The so-called split di-interstitial, which is composed of two nearest neighbor octahedral oxygen interstitials that are distorted in such a way that they dislocate one regular fluorite lattice oxygen ion to form a cluster of triangular geometry, is predicted to be the fundamental building block of the most stable cluster configurations. We also identify how the formation of oxygen defect clusters and the degree of oxidation in AnO{sub 2+x} are both governed by the characer of the An-5f to excess O-2p charger transfer, i.e. the charge transfer to the O-2p orbitals of the interstitial-like (+x) ions, and the ability of the excess O-2p orbitals to hybridize with regular fluorite lattice ions.

  11. Photonic Band Gap in 1D Multilayers Made by Alternating SiO2 or PMMA with monolayer MoS2 or WS2

    E-Print Network [OSTI]

    del Valle, Diana Gisell Figueroa; Scotognella, Francesco

    2015-01-01

    Atomically thin molybdenum disulphide (MoS2) and tungsten disulphide (WS2) are very interesting two dimensional materials for optics and electronics. In this work we show the possibility to obtain one-dimensional photonic crystals consisting of low-cost and easy processable materials, as silicon dioxide (SiO2) or poly methyl methacrylate (PMMA), and monolayers of MoS2 or WS2. We have simulated the transmission spectra of the photonic crystals using the transfer matrix method and employing the wavelength dependent refractive indexes of the materials. This study envisages the experimental fabrication of these new types of photonic crystals for photonic and light emission applications.

  12. Adsorption of water on O(2x2)/Ru(0001): thermal stability and inhibition of dissociation by H2O-O bonding

    SciTech Connect (OSTI)

    Mugarza, Aitor; Shimizu, Tomoko; Cabrera-Sanfelix, Pepa; Sanchez-Portal, Daniel; Arnau, Andres; Salmeron, Miquel

    2008-08-01

    The effect of preadsorbed oxygen on the subsequent adsorption and reactions of water on Ru(0001) has been studied using low temperature scanning tunneling microscopy and DFT calculations. Experiments were carried out for O coverages close to 0.25 ML. It was found that no dissociation of water takes place up to the desorption temperature of {approx}180-230 K. DFT calculations show that intact water on O(2x2)/Ru(0001) is {approx} 0.49 eV more stable than the dissociation products, H and OH, at their preferred fcc and top adsorption sites.

  13. Fluorocarbon assisted atomic layer etching of SiO2 and Si using cyclic Ar/C4F8 and Ar/CHF3 plasma

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Metzler, Dominik; Li, Chen; Engelmann, Sebastian; Bruce, Robert L.; Joseph, Eric A.; Oehrlein, Gottlieb S.

    2015-11-11

    The need for atomic layer etching (ALE) is steadily increasing as smaller critical dimensions and pitches are required in device patterning. A flux-control based cyclic Ar/C4F8 ALE based on steady-state Ar plasma in conjunction with periodic, precise C4F8 injection and synchronized plasma-based low energy Ar+ ion bombardment has been established for SiO2.1 In this work, the cyclic process is further characterized and extended to ALE of silicon under similar process conditions. The use of CHF3 as a precursor is examined and compared to C4F8. CHF3 is shown to enable selective SiO2/Si etching using a fluorocarbon (FC) film build up. Othermore »critical process parameters investigated are the FC film thickness deposited per cycle, the ion energy, and the etch step length. Etching behavior and mechanisms are studied using in situ real time ellipsometry and X-ray photoelectron spectroscopy. Silicon ALE shows less self-limitation than silicon oxide due to higher physical sputtering rates for the maximum ion energies used in this work, ranged from 20 to 30 eV. The surface chemistry is found to contain fluorinated silicon oxide during the etching of silicon. As a result, plasma parameters during ALE are studied using a Langmuir probe and establish the impact of precursor addition on plasma properties.« less

  14. The problem of a metal impurity in an oxide: ab-initio study of electronic and structural properties of Cd in Rutile TiO2

    E-Print Network [OSTI]

    L. Errico; G. Fabricius; M. Renteria

    2007-04-18

    In this work we undertake the problem of a transition metal impurity in an oxide. We present an ab-initio study of the relaxations introduced in TiO2 when a Cd impurity replaces substitutionally a Ti atom. Using the Full-Potential Linearized-Augmented-Plane-Wave method we obtain relaxed structures for different charge states of the impurity and computed the electric-field gradients (EFGs) at the Cd site. We find that EFGs, and also relaxations, are dependent on the charge state of the impurity. This dependence is very remarkable in the case of the EFG and is explained analyzing the electronic structure of the studied system. We predict fairly anisotropic relaxations for the nearest oxygen neighbors of the Cd impurity. The experimental confirmation of this prediction and a brief report of these calculations have recently been presented [P.R.L. 89, 55503 (2002)]. Our results for relaxations and EFGs are in clear contradiction with previous studies of this system that assumed isotropic relaxations and point out that no simple model is viable to describe relaxations and the EFG at Cd in TiO2 even approximately.

  15. Simulation par la théorie de la fonctionnelle de la densité de l'interaction de l'ion uranyle avec les surfaces de $TiO_{2}$ et de $NiFe_{2}O_4$

    E-Print Network [OSTI]

    Perron, Hadrien

    2007-01-01

    Simulation par la théorie de la fonctionnelle de la densité de l'interaction de l'ion uranyle avec les surfaces de $TiO_{2}$ et de $NiFe_{2}O_4$

  16. Layered Li1+x(Ni0.425Mn0.425Co0.15)1xO2 Positive Electrode Materials for Lithium-Ion Batteries

    E-Print Network [OSTI]

    Boyer, Edmond

    Layered Li1+x(Ni0.425Mn0.425Co0.15)1­xO2 Positive Electrode Materials for Lithium-Ion Batteries range decreased with overlithiation Keywords : Although LiCoO2 is suitable for the lithium-ion battery electrochemical performances. Recently lithium-rich manganese-based materials such as Li[NixLi(1/3­2x/3)Mn(2/3­x/3

  17. Local magnetism in the molecule-based metamagnet [Ru2(O2CMe)4]3[Cr(CN)6] probed with implanted muons

    SciTech Connect (OSTI)

    Lancaster, T.; Pratt, F. L.; Blundell, S. J.; Steele, Andrew J.; Baker, Peter J.; Wright, Jack D.; Fishman, Randy Scott; Miller, Joel S.

    2011-01-01

    We present a muon-spin relaxation study of local magnetism in the molecule-based metamagnet [Ru2(O2CMe)4]3[Cr(CN)6]. We observe magnetic order with TN = 33 K, although above 25 K the sublattice spins become less rigid and a degree of static magnetic disorder is observed. The comparison of measurements in applied magnetic field with simulations allows us to understand the origin of the muon response across the metamagnetic transition and to map out the phase diagram of the material. Applied hydrostatic pressures of up to 6 kbar lead to an increase in the local magnetic field along with a complex change in the internal magnetic field distribution.

  18. Neganov-Luke amplified cryogenic light detectors for the background discrimination in neutrinoless double beta decay search with TeO$_{2}$ bolometers

    E-Print Network [OSTI]

    M. Willers; F. v. Feilitzsch; A. Giuliani; A. Gütlein; A. Münster; J. -C. Lanfranchi; L. Oberauer; W. Potzel; S. Roth; S. Schönert; M. v. Sivers; S. Wawoczny; A. Zöller

    2014-11-28

    We demonstrate that Neganov-Luke amplified cryogenic light detectors with Transition Edge Sensor read-out can be applied for the background suppression in cryogenic experiments searching for the neutrinoless double beta decay of $^{130}\\text{Te}$ with TeO$_{2}$ based bolometers. Electron and gamma induced events can be discriminated from $\\alpha$ events by detecting the Cherenkov light produced by the $\\beta$ particles emitted in the decay. We use the Cherenkov light produced by events in the full energy peak of $^{208}\\text{Tl}$ and by events from a $^{147}\\text{Sm}$ source to show that at the Q-value of the neutrinoless double beta decay of $^{130}\\text{Te}$ ($Q_{\\beta \\beta} = 2.53 \\,\\text{MeV}$), a separation of $e^{-}/\\gamma$ events from $\\alpha$ events can be achieved on an event-by-event basis with practically no reduction in signal acceptance.

  19. 15N2 formation and fast oxygen isotope exchange during pulsed 15N18O exposure of MnOx/CeO2

    SciTech Connect (OSTI)

    Kwak, Ja Hun; Szanyi, Janos

    2014-12-23

    Pulsing 15N18O onto an annealed 1% Mn16Ox/Ce16O2 catalyst resulted in very fast oxygen isotope exchange and 15N2 formation at 295 K. In the 1st 15N18O pulse, due to the presence of large number of surface oxygen defects, extensive 15N218O and 15N2 formations were observed. In subsequent pulses oxygen isotope exchange dominated as a result of highly labile oxygen in the oxide. We gratefully acknowledge the US Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy/Vehicle Technologies Program for the support of this work. The research described in this paper was performed at the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated for the US DOE by Battelle.

  20. O2Purge.key

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shinesSolarNewsusceptometer under pressureNavyNumericalO K H A V E N L E C T U

  1. Mathematical Analysis of High-Temperature Co-electrolysis of CO2 and O2 Production in a Closed-Loop Atmosphere Revitalization System

    SciTech Connect (OSTI)

    Michael G. McKellar; Manohar S. Sohal; Lila Mulloth; Bernadette Luna; Morgan B. Abney

    2010-03-01

    NASA has been evaluating two closed-loop atmosphere revitalization architectures based on Sabatier and Bosch carbon dioxide, CO2, reduction technologies. The CO2 and steam, H2O, co-electrolysis process is another option that NASA has investigated. Utilizing recent advances in the fuel cell technology sector, the Idaho National Laboratory, INL, has developed a CO2 and H2O co-electrolysis process to produce oxygen and syngas (carbon monoxide, CO and hydrogen, H2 mixture) for terrestrial (energy production) application. The technology is a combined process that involves steam electrolysis, CO2 electrolysis, and the reverse water gas shift (RWGS) reaction. A number of process models have been developed and analyzed to determine the theoretical power required to recover oxygen, O2, in each case. These models include the current Sabatier and Bosch technologies and combinations of those processes with high-temperature co-electrolysis. The cases of constant CO2 supply and constant O2 production were evaluated. In addition, a process model of the hydrogenation process with co-electrolysis was developed and compared. Sabatier processes require the least amount of energy input per kg of oxygen produced. If co-electrolysis replaces solid polymer electrolyte (SPE) electrolysis within the Sabatier architecture, the power requirement is reduced by over 10%, but only if heat recuperation is used. Sabatier processes, however, require external water to achieve the lower power results. Under conditions of constant incoming carbon dioxide flow, the Sabatier architectures require more power than the other architectures. The Bosch, Boudouard with co-electrolysis, and the hydrogenation with co-electrolysis processes require little or no external water. The Bosch and hydrogenation processes produce water within their reactors, which aids in reducing the power requirement for electrolysis. The Boudouard with co-electrolysis process has a higher electrolysis power requirement because carbon dioxide is split instead of water, which has a lower heat of formation. Hydrogenation with co-electrolysis offers the best overall power performance for two reasons: it requires no external water, and it produces its own water, which reduces the power requirement for co-electrolysis.

  2. Auxiliary Ligand-Dependent Assembly of Several Ni/Ni-Cd Compounds with N2O2 Donor Tetradentate Symmetrical Schiff Base Ligand

    SciTech Connect (OSTI)

    Ge, Ying Ying; Li, Guo-Bi; Fang, Hua-Cai; Zhan, Xu Lin; Gu, Zhi-Gang; Chen, Jin Hao; Sun, Feng; Cai, Yue-Peng; Thallapally, Praveen K.

    2010-09-18

    Several low-dimensional Ni/Ni-Cd complexes containing N2O2 donor tetradentate symmetrical Schiff base ligand bis(acetylacetone)ethylene-diamine (sy-H2L2), namely, [Ni(sy-L2)]2?HLa?ClO4 (2), (HLa)2?(ClO4)?(NO3) (3), [Ni(sy-L2)X]2](4,4’-bipy) (where La = 5,7-dimethyl-3,6-dihydro-2H-1,4-diazepine, X = ClO4 (4), X=NO3 (5), [Ni(sy-L2)Cd(SCN)2]n (6) and [Ni(sy-L2)?Cd(N3)2]n (7) have been synthesized from [Ni(sy-L2)]2?H2O (1). Complex 2, is three component discrete assembly generated from (HLa)+ moiety bridged with [Ni(sy-L2)] unit and ClO4- anion. A solution containing complex 2 and Cd(NO3)2 results in a mixture of 1 and 3. Further re-crystallization of 1 and 3 with various auxiliary ligands, provides coordination complexes 4 – 7 stabilized by weak hydrogen bonds in which 6 and 7 represent the first 1D heteronuclear complexes based on symmetric acacen-base Schiff base ligand.

  3. One-step electrochemical deposition of a graphene-ZrO2 nanocomposite: Preparation, characterization and application for detection of organophosphorus agents

    SciTech Connect (OSTI)

    Du, Dan; Liu, Juan; Zhang, Xiao-Yan; Cui, Xiao-Li; Lin, Yuehe

    2011-04-27

    This paper described the preparation, characterization, and electrochemical properties of a graphene-ZrO2 nanocomposite (GZN) and its application for both the enrichment and detection of methyl parathion (MP). GZN was fabricated using electrochemical deposition and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), which showed the successful formation of nanocomposites. Due to the strong affinity to the phosphoric group and the fast electron-transfer kinetics of GZN, both the extraction and electrochemical detection of organophosphorus (OP) agents at the same GZN modified electrochemical sensor was possible. The combination of solid-phase extraction and stripping voltammetric analysis allowed fast, sensitive, and selective determination of MP in garlic samples. The stripping response was highly linear over the MP concentrations ranging from 0.5 ng mL?1 to 100 ng mL?1, with a detection limit of 0.1 ng mL?1. This new nanocomposite-based electrochemical sensor provides an opportunity to develop a field-deployable, sensitive, and quantitative method for monitoring exposure to OPs.

  4. A New Equation of State for CCS Pipeline Transport: Calibration of Mixing Rules for Binary Mixtures of CO2 with N2, O2 and H2

    E-Print Network [OSTI]

    Demetriades, Thomas A

    2015-01-01

    One of the aspects currently holding back commercial scale deployment of carbon capture and storage (CCS) is an accurate understanding of the thermodynamic behaviour of carbon dioxide and relevant impurities during the pipeline transport stage. In this article we develop a general framework for deriving pressure-explicit EoS for impure CO2. This flexible framework facilitates ongoing development of custom EoS in response to new data and computational applications. We use our method to generalise a recent EoS for pure CO2 [Demetriades et al. Proc IMechE Part E, 227 (2013) pp. 117] to binary mixtures with N2, O2 and H2, obtaining model parameters by fitting to experiments made under conditions relevant to CCS-pipeline transport. Our model pertains to pressures up to 16MPa and temperatures between 273K and the critical temperature of pure CO2. In this region, we achieve close agreement with experimental data. When compared to the GERG EoS, our EoS has a comparable level of agreement with CO2 -N2 VLE experiments ...

  5. Use of Sm-123 + Sm-211 Mixed-powder Buffers to Assist the Growth of SmBCO and ZrO2-doped SmBCO Single Grain, Bulk Superconductors

    E-Print Network [OSTI]

    Zhao, Wen; Shi, Yunhua; Dennis, Anthony R.; Cardwell, David A.

    2014-12-18

    motorized pestle and mortar was used to mix thoroughly powders of composition (75 wt% Sm-123 + 25 wt% Sm-211) + 2 wt% BaO2 + 1 wt% CeO2, prior to being pressed uniaxially under a pressure of 1.5 tons into a green pre-form (pellet-like) with diameters... of 20 mm and 25 mm and thicknesses of 9 mm and 12.5 mm (each pellet shrinks to about 80 % of its original size after TSMG, corresponding to as processed dimensions of 16 mm and 20 mm diameter and 7 mm and 10 mm thickness). Doped green pellets were...

  6. Structural Underpinnings of the Enhanced Cycling Stability upon Al-Substitution in LiNi0.45Mn0.45Co0.1-yAlyO2 Positive Electrode Materials for Li-ion Batteries

    E-Print Network [OSTI]

    Conry, Thomas E.

    2013-01-01

    materials for Li-ion batteries Thomas E. Conry, a,b Apurvamaterials in Li-ion batteries. Synchrotron-based high-materials for Li-ion batteries. LiNi z Mn z Co 1-2z O 2 (NMC

  7. Improved thermal stability of LiCoO2 by nanoparticle AlPO4 coating with respect to spinel Li1:05Mn1:95O4

    E-Print Network [OSTI]

    Cho, Jaephil

    secondary batteries has rapidly expanded due to their applicability to mobile electron- ics batteries use LiCoO2 as a cathode material due to the higher volumetric energy density and excel- lent, resulting in oxygen generation [7]. In addition, the deposited lithium on the graphite anode increases

  8. Qualitative Aspects of the Solutions of a Mathematical Model for the Dynamic Analysis of the Reversible Chemical Reaction SO2(g)+1/2O2(g)SO3(g) in a Catalytic Reactor

    E-Print Network [OSTI]

    Angulo Wilfredo; Contreras Joyne

    2014-12-19

    We present some qualitative aspects concerning the solution to the mathematical model describing the dynamical behavior of the reversible chemical reaction SO2(g)+1/2O2(g)SO3(g) carried out in a catalytic reactor used in the process of sulfuric acid production.

  9. Qualitative Aspects of the Solutions of a Mathematical Model for the Dynamic Analysis of the Reversible Chemical Reaction SO2(g)+1/2O2(g)SO3(g) in a Catalytic Reactor

    E-Print Network [OSTI]

    Wilfredo, Angulo

    2014-01-01

    We present some qualitative aspects concerning the solution to the mathematical model describing the dynamical behavior of the reversible chemical reaction SO2(g)+1/2O2(g)SO3(g) carried out in a catalytic reactor used in the process of sulfuric acid production.

  10. Structural changes and thermal stability of charged LiNixMnyCozO2 cathode materials studied by combined in situ time-resolved XRD and mass spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bak, Seong -Min; Hu, Enyuan; Zhou, Yongning; Yu, Xiqian; Senanayake, Sanjaya D.; Cho, Sung -Jin; Kim, Kwang -Bum; Chung, Kyung Yoon; Yang, Xiao -Qing; Nam, Kyung -Wan

    2014-11-24

    Thermal stability of charged LiNixMnyCozO2 (NMC, with x + y + z = 1, x:y:z = 4:3:3 (NMC433), 5:3:2 (NMC532), 6:2:2 (NMC622), and 8:1:1 (NMC811)) cathode materials is systematically studied using combined in situ time- resolved X-ray diffraction and mass spectroscopy (TR-XRD/MS) techniques upon heating up to 600 °C. The TR-XRD/MS results indicate that the content of Ni, Co, and Mn significantly affects both the structural changes and the oxygen release features during heating: the more Ni and less Co and Mn, the lower the onset temperature of the phase transition (i.e., thermal decomposition) and the larger amount of oxygenmore »release. Interestingly, the NMC532 seems to be the optimized composition to maintain a reasonably good thermal stability, comparable to the low-nickel-content materials (e.g., NMC333 and NMC433), while having a high capacity close to the high-nickel-content materials (e.g., NMC811 and NMC622). The origin of the thermal decomposition of NMC cathode materials was elucidated by the changes in the oxidation states of each transition metal (TM) cations (i.e., Ni, Co, and Mn) and their site preferences during thermal decomposition. It is revealed that Mn ions mainly occupy the 3a octahedral sites of a layered structure (R3?m) but Co ions prefer to migrate to the 8a tetrahedral sites of a spinel structure (Fd3¯m) during the thermal decomposition. Such element-dependent cation migration plays a very important role in the thermal stability of NMC cathode materials. The reasonably good thermal stability and high capacity characteristics of the NMC532 composition is originated from the well-balanced ratio of nickel content to manganese and cobalt contents. As a result, this systematic study provides insight into the rational design of NMC-based cathode materials with a desired balance between thermal stability and high energy density.« less

  11. Stephan Klemme Hugh St.C. O'Neill The reaction MgCr2O4 + SiO2 = Cr2O3 + MgSiO3 and the free energy

    E-Print Network [OSTI]

    bar and 298 K (J molA1 ) DG Gibbs free energy change for a reaction among pure end membersStephan Klemme á Hugh St.C. O'Neill The reaction MgCr2O4 + SiO2 = Cr2O3 + MgSiO3 and the free energy of formation of magnesiochromite (MgCr2O4) Received: 9 May 1997 / Accepted: 28 July 1997 Abstract

  12. 26 E N G I N E E R I N G & S C I E N C E N O . 2 2 0 0 8 We know how to make electricity from sun-

    E-Print Network [OSTI]

    Faraon, Andrei

    26 E N G I N E E R I N G & S C I E N C E N O . 2 2 0 0 8 We know how to make electricity from sun the sun is shining, we could use it after dark, and the storage problem would be solved. Specifically, I and oxygen gas bubbling up from the anode. We want to do the same thing as grownups, but using the sun as our

  13. MS Exam, Spring 2014, Solid State Electronics (ECE 103) 5. (15 points, 3 points each) 1. The energy band diagram for a p-Si/SiO2/n-Si capacitor

    E-Print Network [OSTI]

    California at San Diego, University of

    MS Exam, Spring 2014, Solid State Electronics (ECE 103) 5. (15 points, 3 points each) 1. The energy band diagram for a p-Si/SiO2/n-Si capacitor (SOS-C) under flat-band conditions is given below. The SOS to the device. (c) Same as (b) except now a large negative voltage is applied to the gate. #12;MS Exam, Spring

  14. Nanoscale Phase Separation, Cation Ordering, and Surface Oxygen Chemistry in Pristine Li1.2Ni0.2Mn0.6O2 for Li-Ion Batteries

    SciTech Connect (OSTI)

    Gu, Meng; Genc, Arda; Belharouak, Ilias; Wang, Dapeng; Amine, Khalil; Thevuthasan, Suntharampillai; Baer, Donald R.; Zhang, Jiguang; Browning, Nigel D.; Liu, Jun; Wang, Chong M.

    2013-05-14

    Li-rich layered material Li1.2Ni0.2Mn0.6O2 possesses high voltage and high specific capacity, which makes it an attractive candidate for the transportation industry and sustainable energy storage systems. The rechargeable capacity of the Li-ion battery is linked largely to the structural stability of the cathode materials during the charge-discharge cycles. However, the structure and cation distribution in pristine (un-cycled) Li1.2Ni0.2Mn0.6O2 have not yet been fully characterized. Using a combination of aberration-corrected scanning/transmission electron microscopy, X-ray dispersive energy spectroscopy (XEDS), electron energy loss spectroscopy (EELS), and complementary multislice image simulation, we have probed the crystal structure, cation/anion distribution, and electronic structure of Li1.2Ni0.2Mn0.6O2 nanoparticle. We discovered that the electronic structure and valence state of transition metal ions show significant variations, which have been identified to be attributed to the oxygen deficiency near the particle surfaces. Characterization of the nanoscale phase separation and cation ordering in the pristine material are critical for understanding the capacity and voltage fading of this material for battery application.

  15. Hydrogen donors in SnO2 studied by infrared spectroscopy and first-principles calculations W. M. Hlaing Oo,1 S. Tabatabaei,1 M. D. McCluskey,1,* J. B. Varley,2 A. Janotti,3 and C. G. Van de Walle3,

    E-Print Network [OSTI]

    McCluskey, Matthew

    Hydrogen donors in SnO2 studied by infrared spectroscopy and first-principles calculations W. M; revised manuscript received 8 October 2010; published 3 November 2010 Hydrogen is a potentially important source of n-type conductivity in oxide materials. We have investigated hydrogen in tin oxide SnO2

  16. The Impact of Aluminum and Iron Substitution on the Structure and Electrochemistry of Li[Ni0.4Co0.2-yMyMn0.4]O2 Materials

    SciTech Connect (OSTI)

    WIlcox, James D.; Rodriguez, Efrain E.; Doeff, Marca M.

    2009-07-23

    Li[Ni0.4Co0.2-yMyMn0.4]O2 (0<_y<_0.2) (M=Al) and Li[Ni0.4Co0.15Fe0.05Mn0.4]O2 compounds were prepared in order to investigate the effect of replacement of all or part of the cobalt on the structural and electrochemical properties. The impact of substitution on the structure has been examined by both x-ray and neutron diffraction experiments. The incorporation of aluminum has minimal effect on the anti-site defect concentration, but leads to structural changes that affect electrochemical performance. The most important effect is an opening of the lithium slab dimension upon substitution, which results in improved rate performance compared to the parent compound. In contrast, the lithium slab dimension is not affected by iron substitution and no rate enhancement effect is observed. The cycling stability of aluminum containing materials is superior to both the parent material and iron-substituted materials.

  17. Density functional theory simulations of amorphous high-oxides on a compound semiconductor alloy: a-Al2O3/InGaAs(100)-(42), a-HfO2/InGaAs(100)-(42), and a-

    E-Print Network [OSTI]

    Kummel, Andrew C.

    atomic layer deposition Appl. Phys. Lett. 104, 042904 (2014); 10.1063/1.4863440 Si passivation effects x 0.53 ) and atomic-layer deposited Al 2 O 3 and HfO 2 Appl. Phys. Lett. 94, 202110 (2009); 10.1063/1.3137187 Energy-band parameters of atomic layer deposited Al 2 O 3 and HfO 2 on In x Ga 1 - x As Appl. Phys. Lett

  18. Eliminating Voltage Decay of Lithium-Rich Li1.14Mn0.54Ni0.14Co0.14O2 Cathodes by Controlling the Electrochemical Process

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wei, Z.; Zhu, Y.; Zhang, W.; Wang, F.; Zhang, Q.; Qiu, B.; Han, S.; Xia, Y.; Liu, Z.

    2015-03-27

    Lithium-rich material owns a particularly high capacity owing to the activation of electrochemical inactive Li2MnO3 phase. But at the same time, MnO2 phase formed after Li2MnO3 activation confronts a severe problem of converting to spinel phase, and resulting in voltage decay. To our knowledge, this phenomenon is inherent property of layered manganese oxide materials and can hardly be overcome. Based on this, unlike previous reports, herein we design a method for the first time to accelerate the phase transformation by tuning the charge upper-limit voltage at a high value, so the phase transformation process can be finished in a fewmore »cycles. Then material structure remains stable while cycling at a low upper-limit voltage. By this novel method voltage decay is eliminated significantly.« less

  19. Hardware Design Techniques for Securing and Synthesizing Resource-Constrained IoT Systems

    E-Print Network [OSTI]

    Wendt, James Bradley

    2015-01-01

    121 FoundryRange and Magnitude Foundry Identification . . . . . . . . .133 IC parameters and foundry profiles. Circuit 1 originates

  20. Hardware Design Techniques for Securing and Synthesizing Resource-Constrained IoT Systems

    E-Print Network [OSTI]

    Wendt, James Bradley

    2015-01-01

    represents gates on the critical path and the bluescenario we purposely dope the critical path gates at lowersavings as NTC, the critical path gates are biased and

  1. Hardware Design Techniques for Securing and Synthesizing Resource-Constrained IoT Systems

    E-Print Network [OSTI]

    Wendt, James Bradley

    2015-01-01

    and T. Starner, “Energy scavenging for mobile and wireless50 Hz. CHAPTER 6 Energy Harvesting Wireless sensing networksrafzadeh, “Energy optimization in wireless medical systems

  2. Hardware Design Techniques for Securing and Synthesizing Resource-Constrained IoT Systems

    E-Print Network [OSTI]

    Wendt, James Bradley

    2015-01-01

    The Internet of Things . . . . . . . . .Industrial Internet and Internet of Things | GE Software. ”technolo- gies and the Internet of Things,” in Proceedings

  3. O3-type layered transition metal oxide Na(NiCoFeTi)1/4O2 as a high rate and long cycle life cathode material for sodium ion batteries

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yue, Ji -Li; Yang, Xiao -Qing; Zhou, Yong -Ning; Yu, Xiqian; Bak, Seong -Min; Fu, Zheng -Wen

    2015-10-09

    High rate capability and long cycle life are challenging goals for the development of room temperature sodium-ion batteries. Here we report a new single phase quaternary O3-type layer-structured transition metal oxide Na(NiCoFeTi)1/4O2 synthesized by a simple solid-state reaction as a new cathode material for sodium-ion batteries. It can deliver a reversible capacity of 90.6 mA h g–1 at a rate as high as 20C. At 5C, 75.0% of the initial specific capacity can be retained after 400 cycles with a capacity-decay rate of 0.07% per cycle, demonstrating a superior long-term cyclability at high current density. X-ray diffraction and absorption characterizationmore »revealed reversible phase transformations and electronic structural changes during the Na+ deintercalation/intercalation process. Ni, Co and Fe ions contribute to charge compensation during charge and discharge. Although Ti ions do not contribute to the charge transfer, they play a very important role in stabilizing the structure during charge and discharge by suppressing the Fe migration. Additionally, Ti substitution can also smooth the charge–discharge plateaus effectively, which provides a potential advantage for the commercialization of this material for room temperature sodium-ion batteries.« less

  4. Using real-time electron microscopy to explore the effects of transition-metal composition on the local thermal stability in charged LixNiyMnzCo1-y-zO2 cathode materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hwang, Sooyeon; Kim, Seung Min; Bak, Seong -Min; Kim, Se Young; Cho, Byung -Won; Chung, Kyung Yoon; Lee, Jeong Yong; Stach, Eric A.; Chang, Wonyoung

    2015-05-08

    In this study, we use in-situ transmission electron microcopy (TEM) to investigate the thermal decomposition that occurs at the surface of charged LixNiyMnzCo1-y-zO2 (NMC) cathode materials of different composition (with y, z=0.8, 0.1 and 0.6, 0.2 and 0.4, 0.3), after they have been charged to their practical upper limit voltage (4.3V). By heating these materials inside the TEM, we are able to directly characterize near surface changes in both their electronic structure (using electron energy loss spectroscopy) and crystal structure and morphology (using electron diffraction and bright-field imaging). The most Ni-rich material (y, z = 0.8, 0.1) is found tomore »be thermally unstable at significantly lower temperatures than the other compositions – this is manifested by changes in both the electronic structure and the onset of phase transitions at temperatures as low as 100°C. Electron energy loss spectroscopy indicates that the thermally induced reduction of Ni ions drives these changes, and that this is exacerbated by the presence of an additional redox reaction that occurs at 4.2V in the y, z = 0.8, 0.1 material. Exploration of individual particles shows that there are substantial variations in the onset temperatures and overall extent of these changes. Of the compositions studied, the composition of y, z = 0.6, 0.2 has the optimal combination of high energy density and reasonable thermal stability. The observations herein demonstrate that real time electron microscopy provide direct insight into the changes that occur in cathode materials with temperature, allowing optimization of different alloy concentrations to maximize overall performance.« less

  5. All Inkjet-Printed SnO2/ZrO2 Transistors

    E-Print Network [OSTI]

    Jang, Jaewon

    2013-01-01

    Rhee, K. Yong, “Atomic layer deposition of hafnium silicatefilms grown by atomic layer Deposition,” Journal of Applied

  6. Structural Changes and Thermal Stability of Charged LiNix Mny CozO2 Cathode Materials Studied by Combined In Situ Time-Resolved XRD and Mass Spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bak, Seong-Min; Hu, Enyuan; Zhou, Yongning; Yu, Xiqian; Senanayake, Sanjaya D.; Cho, Sung-Jin; Kim, Kwang-Bum; Chung, Kyung Yoon; Yang, Xiao-Qing; Nam, Kyung-Wan

    2014-11-24

    Thermal stability of charged LiNixMnyCozO2 (NMC, with x + y + z = 1, x:y:z = 4:3:3 (NMC433), 5:3:2 (NMC532), 6:2:2 (NMC622), and 8:1:1 (NMC811)) cathode materials is systematically studied using combined in situ time- resolved X-ray diffraction and mass spectroscopy (TR-XRD/MS) techniques upon heating up to 600 °C. The TR-XRD/MS results indicate that the content of Ni, Co, and Mn significantly affects both the structural changes and the oxygen release features during heating: the more Ni and less Co and Mn, the lower the onset temperature of the phase transition (i.e., thermal decomposition) and the larger amount of oxygenmore »release. Interestingly, the NMC532 seems to be the optimized composition to maintain a reasonably good thermal stability, comparable to the low-nickel-content materials (e.g., NMC333 and NMC433), while having a high capacity close to the high-nickel-content materials (e.g., NMC811 and NMC622). The origin of the thermal decomposition of NMC cathode materials was elucidated by the changes in the oxidation states of each transition metal (TM) cations (i.e., Ni, Co, and Mn) and their site preferences during thermal decomposition. It is revealed that Mn ions mainly occupy the 3a octahedral sites of a layered structure (R3?-m) but Co ions prefer to migrate to the 8a tetrahedral sites of a spinel structure (Fd3-m) during the thermal decomposition. Such element-dependent cation migration plays a very important role in the thermal stability of NMC cathode materials. The reasonably good thermal stability and high capacity characteristics of the NMC532 composition is originated from the well-balanced ratio of nickel content to manganese and cobalt contents. This systematic study provides insight into the rational design of NMC-based cathode materials with a desired balance between thermal stability and high energy density.« less

  7. Structural Changes and Thermal Stability of Charged LiNix Mny CozO2 Cathode Materials Studied by Combined In Situ Time-Resolved XRD and Mass Spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bak, Seong-Min [Brookhaven National Lab. (BNL), Upton, NY (United States); Hu, Enyuan [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhou, Yongning [Brookhaven National Lab. (BNL), Upton, NY (United States); Yu, Xiqian [Brookhaven National Lab. (BNL), Upton, NY (United States); Senanayake, Sanjaya D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Cho, Sung-Jin [Johnson Control Advanced Power Solution, Milwaukee, WI (United States); North Carolina A&T Univ., Greensboro, NC (United States). Joint School of Nano Science and Nano Engineering; Kim, Kwang-Bum [Yonsei Univ., Seoul, (Korea, Republic of). Dept of Material Science and Engineering; Chung, Kyung Yoon [Korea Inst. of Science and Technology (KIST), Seoul (Korea, Republic of); Yang, Xiao-Qing [Brookhaven National Lab. (BNL), Upton, NY (United States); Nam, Kyung-Wan [Dongguk Univ., Seoul (Korea, Republic of); Dept. of Energy and Materials Engineering

    2014-12-24

    Thermal stability of charged LiNixMnyCozO2 (NMC, with x + y + z = 1, x:y:z = 4:3:3 (NMC433), 5:3:2 (NMC532), 6:2:2 (NMC622), and 8:1:1 (NMC811)) cathode materials is systematically studied using combined in situ time- resolved X-ray diffraction and mass spectroscopy (TR-XRD/MS) techniques upon heating up to 600 °C. The TR-XRD/MS results indicate that the content of Ni, Co, and Mn significantly affects both the structural changes and the oxygen release features during heating: the more Ni and less Co and Mn, the lower the onset temperature of the phase transition (i.e., thermal decomposition) and the larger amount of oxygen release. Interestingly, the NMC532 seems to be the optimized composition to maintain a reasonably good thermal stability, comparable to the low-nickel-content materials (e.g., NMC333 and NMC433), while having a high capacity close to the high-nickel-content materials (e.g., NMC811 and NMC622). The origin of the thermal decomposition of NMC cathode materials was elucidated by the changes in the oxidation states of each transition metal (TM) cations (i.e., Ni, Co, and Mn) and their site preferences during thermal decomposition. It is revealed that Mn ions mainly occupy the 3a octahedral sites of a layered structure (R3?-m) but Co ions prefer to migrate to the 8a tetrahedral sites of a spinel structure (Fd3-m) during the thermal decomposition. Such element-dependent cation migration plays a very important role in the thermal stability of NMC cathode materials. The reasonably good thermal stability and high capacity characteristics of the NMC532 composition is originated from the well-balanced ratio of nickel content to manganese and cobalt contents. This systematic study provides insight into the rational design of NMC-based cathode materials with a desired balance between thermal stability and high energy density.

  8. Hydrothermally Stable, Sulfur-Tolerant Platinum-Based Oxidation Catalysts via Surface Modification of SiO2 with TiO2 and ZrO2

    Broader source: Energy.gov [DOE]

    This study demonstrates the feasibility of developing highly stable, sulfur-tolerant oxidation catalysts that use less Pt via surface modification of silica supports with transition metal oxides.

  9. Internet of Systems (IoS) - Economic Re-equilibration Catalyzed by Internet of Things (IoT)

    E-Print Network [OSTI]

    Datta, Shoumen

    2014-01-01

    How will the tapestry of humanity and the ethos of civilization evolve when billions of devices and trillions of sensors with quadrillion end points can connect events in our daily lives to the world around us and monitor ...

  10. Inkjet-printed "Zero-Power" Wireless Sensor and Power Management Nodes for IoT and "Smart Skin" Applications

    E-Print Network [OSTI]

    Tentzeris, Manos

    Engineering, Georgia Institute of Technology, Atlanta, USA (etentze@ece.gatech.edu) 3 Centre Tecnologic de

  11. Shipboard Atmospheric O2 Measurements in the Southern Ocean

    E-Print Network [OSTI]

    Stephens, Britton B.

    outgassing on the atmospheric gradients at this latitude and time of year. This CO2 outgassing is in contrast

  12. Effects of Support Composition and Pretreatment Conditions on the Structure of Vanadia Dispersed on SiO2, Al2O3, TiO2, ZrO2, and HfO2

    E-Print Network [OSTI]

    Iglesia, Enrique

    , including the selective reduction of NOx with ammonia and the oxidative dehydroge- nation of alkanes.1-visible) were utilized to monitor the effect of adsorbed water, calcination temperature, and reduction in H2 a phase transition from tetragonal to monoclinic. H2 reduction produced limited changes in the structure

  13. Nature of =~SiOCrO(2)CI And (=~SiO)(2)CrO(2) Sites Prepared By Grafting CrO(2)CI(2) Onto Silica

    SciTech Connect (OSTI)

    Demmelmaier, C.A.; White, R.E.; Bokhoven, J.A.van; Scott, S.L.

    2009-05-14

    The room-temperature reaction between chromyl chloride and Sylopol 952 silicas pretreated at 200, 450, and 800 C was investigated using IR, XANES, and EXAFS spectroscopy, as well as by DFT modeling. On the silicas pretreated at 200 and 450 C, the structurally uniform sites formed by the reaction with one surface hydroxyl group are described as {triple_bond}SiOCrO{sub 2}Cl. Unreacted silanols persist on these silicas even in the presence of excess CrO{sub 2}Cl{sub 2}, and on the silica pretreated at 200 C some participate in hydrogen bonding with the grafted monochlorochromate sites. On the silica pretreated at 800 C, both {triple_bond}SiOCrO{sub 2}Cl and ({triple_bond}SiO){sub 2}CrO{sub 2} sites are formed. The latter are produced despite the absence of hydrogen-bonded hydroxyl pairs on the support. The origin of the chromate sites is proposed to be the reaction between CrO{sub 2}Cl{sub 2} and hydroxyl-substituted siloxane 2-rings. These rings are likely formed at 800 C by condensation between a pair of vicinal silanols in which one of the silanols is also a member of a geminal pair.

  14. Small, Inexpensive Combined NOx Sensor and O2 Sensor

    SciTech Connect (OSTI)

    W. N. Lawless; C. F. Clark, Jr.

    2008-09-08

    It has been successfully demonstrated in this program that a zirconia multilayer structure with rhodium-based porous electrodes performs well as an amperometric NOx sensor. The sensitivity of the sensor bodies operating at 650 to 700 C is large, with demonstrated current outputs of 14 mA at 500 ppm NOx from sensors with 30 layers. The sensor bodies are small (4.5 x 4.2 x 3.1 mm), rugged, and inexpensive. It is projected the sensor bodies will cost $5 - $10 in production. This program has built on another successful development program for an oxygen sensor based on the same principles and sponsored by DOE. This oxygen sensor is not sensitive to NOx. A significant technical hurdle has been identified and solved. It was found that the 100% Rh electrodes oxidize rapidly at the preferred operating temperatures of 650 - 700 C, and this oxidation is accompanied by a volume change which delaminates the sensors. The problem was solved by using alloys of Rh and Pt. It was found that a 10%/90% Rh/Pt alloy dropped the oxidation rate of the electrodes by orders of magnitude without degrading the NOx sensitivity of the sensors, allowing long-term stable operation at the preferred operating temperatures. Degradation in the sensor output caused by temperature cycling was identified as a change in resistance at the junction between the sensor body and the external leads attached to the sensor body. The degradation was eliminated by providing strong mechanical anchors for the wire and processing the junctions to obtain good electrical bonds. The NOx sensors also detect oxygen and therefore the fully-packaged sensor needs to be enclosed with an oxygen sensor in a small, heated zirconia chamber exposed to test gas through a diffusion plug which limits the flow of gas from the outside. Oxygen is pumped from the interior of the chamber to lower the oxygen content and the combination of measurements from the NOx and oxygen sensors yields the NOx content of the gas. Two types of electronic control units were designed and built. One control unit provides independent constant voltages to the NOx and oxygen sensors and reads the current from them (that is, detects the amount of test gas present). The second controller holds the fully-assembled sensor at the desired operating temperature and controllably pumps excess oxygen from the test chamber. While the development of the sensor body was a complete success, the development of the packaging was only partially successful. All of the basic principles were demonstrated, but the packaging was too complex to optimize the operation within the resources of the program. Thus, no fully-assembled sensors were sent to outside labs for testing of cross-sensitivities, response times, etc. Near the end of the program, Sensata Technologies of Attleboro, MA tested the sensor bodies and confirmed the CeramPhysics measurements as indicated in the following attached letter. Sensata was in the process of designing their own packaging for the sensor and performing cross-sensitivity tests when they stopped all sensor development work due to the automotive industry downturn. Recently Ceramatec Inc. of Salt Lake City has expressed an interest in testing the sensor, and other licensing opportunities are being pursued.

  15. Small, Inexpensive Combined NOx and O2 Sensor

    SciTech Connect (OSTI)

    W. Lawless; C. Clark

    2008-09-01

    It has been successfully demonstrated in this program that a zirconia multilayer structure with rhodium-based porous electrodes performs well as an amperometric NO{sub x} sensor. The sensitivity of the sensor bodies operating at 650 to 700 C is large, with demonstrated current outputs of 14 mA at 500 ppm NO{sub x} from sensors with 30 layers. The sensor bodies are small (4.5 x 4.2 x 3.1 mm), rugged, and inexpensive. It is projected the sensor bodies will cost $5-$10 in production. This program has built on another successful development program for an oxygen sensor based on the same principles and sponsored by DOE. This oxygen sensor is not sensitive to NO{sub x}. A significant technical hurdle has been identified and solved. It was found that the 100% Rh electrodes oxidize rapidly at the preferred operating temperatures of 650-700 C, and this oxidation is accompanied by a volume change which delaminates the sensors. The problem was solved by using alloys of Rh and Pt. It was found that a 10%/90% Rh/Pt alloy dropped the oxidation rate of the electrodes by orders of magnitude without degrading the NO{sub x} sensitivity of the sensors, allowing long-term stable operation at the preferred operating temperatures. Degradation in the sensor output caused by temperature cycling was identified as a change in resistance at the junction between the sensor body and the external leads attached to the sensor body. The degradation was eliminated by providing strong mechanical anchors for the wire and processing the junctions to obtain good electrical bonds. The NO{sub x} sensors also detect oxygen and therefore the fully-packaged sensor needs to be enclosed with an oxygen sensor in a small, heated zirconia chamber exposed to test gas through a diffusion plug which limits the flow of gas from the outside. Oxygen is pumped from the interior of the chamber to lower the oxygen content and the combination of measurements from the NO{sub x} and oxygen sensors yields the NO{sub x} content of the gas. Two types of electronic control units were designed and built. One control unit provides independent constant voltages to the NOx and oxygen sensors and reads the current from them (that is, detects the amount of test gas present). The second controller holds the fully-assembled sensor at the desired operating temperature and controllably pumps excess oxygen from the test chamber. While the development of the sensor body was a complete success, the development of the packaging was only partially successful. All of the basic principles were demonstrated, but the packaging was too complex to optimize the operation within the resources of the program. Thus, no fully-assembled sensors were sent to outside labs for testing of cross-sensitivities, response times, etc. Near the end of the program, Sensata Technologies of Attleboro, MA tested the sensor bodies and confirmed the CeramPhysics measurements as indicated in the following attached letter. Sensata was in the process of designing their own packaging for the sensor and performing cross-sensitivity tests when they stopped all sensor development work due to the automotive industry downturn. Recently Ceramatec Inc. of Salt Lake City has expressed an interest in testing the sensor, and other licensing opportunities are being pursued.

  16. An Organometallic Synthesis of TiO2 Nanoparticles

    E-Print Network [OSTI]

    Physics and Applied Mathematics, and Materials Research Science & Engineering Center, Columbia Uni titania.8 This approach has recently been extended to zirconia,9 hafnia, and mixed group 4 oxides.10

  17. Catalytic H2O2 decomposition on palladium surfaces 

    E-Print Network [OSTI]

    Salinas, S. Adriana

    1998-01-01

    The catalytic decomposition of H?O? at smooth single-crystal and polycrystalline palladium surfaces that had been subjected to various surface modifications has been studied. Monolayer and submonolayer coverages of I, Br and Cl adsorbates were used...

  18. Highly-Selective and Reversible O2 Binding in

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you notHeat Pumps Heat Pumps An errorSeparationsRelevant to

  19. Photoinduced electron transfer in perylene-TiO2 nanoassemblies

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJesseworkSURVEYI/OPerformance andAreaPhotoinduced electron transfer in

  20. Low Cost TiO2 Nanoparticles - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousand CubicResourcelogoFeet) DeliveriesSubstrates -Solar

  1. TiO2-based sensor arrays modeled with nonlinear regression analysis for simultaneously determining CO and O2

    E-Print Network [OSTI]

    Dutta, Prabir K.

    (CISM), The Ohio State University, 120 West 18th Avenue, Columbus, OH 43210, USA b Department of Physics, Center for Industrial Sensors and Measurements (CISM), The Ohio State University, 174 West 18th Avenue

  2. Reactivity of Au nanoparticles supported over SiO2 and TiO2 studiedby ambient pressure photoelectron spectroscopy

    SciTech Connect (OSTI)

    Herranz, Tirma; Deng, Xingyi; Cabot, Andreu; Alivisatos, Paul; Liu, Zhi; Soler-Illia, Galo; Salmeron, Miquel

    2009-04-15

    The influence of the metal cluster size and the identity of the support on the reactivity of gold based catalysts have been studied in the CO oxidation reaction. To overcome the structural complexity of the supported catalysts, gold nanoparticles synthesized from colloidal chemistry with precisely controlled size have been used. Those particles were supported over SiO{sub 2} and TiO{sub 2} and their catalytic activity was measured in a flow reactor. The reaction rate was dependent on the particle size and the support, suggesting two reaction pathways in the CO oxidation reaction. In parallel, ambient pressure photoelectron spectroscopy (APPS) has been performed under reaction conditions using bidimensional model catalysts prepared upon supporting the Au nanoparticles over planar polycrystalline SiO{sub 2} and TiO{sub 2} thin films by means of the Langmuir-Blodgett (LB) technique to mimic the characteristic of the powder samples. In this way, the catalytically active surface was characterized under true reaction conditions, revealing that during CO oxidation gold remains in the metallic state.

  3. ORIGINAL PAPER SiO2TiO2 xerogels for tailoring the release of brilliant blue FCF

    E-Print Network [OSTI]

    Cao, Guozhong

    , and biological materi- als. For example, carbon fiber [7] has been used to adsorb various acidic and basic dyes coatings on metals [11­13], and abrasion resistant coatings on plastics [14]. Silica or silica-based hybrid

  4. Measurements and analysis of CO and O2 emissions in CH4/CO2/O2 flames

    E-Print Network [OSTI]

    Lieuwen, Timothy C.

    accommodate carbon dioxide capture and sequestration. Oxy-fuel combustion, where the fuel is combusted Inc. All rights reserved. Keywords: Oxy-fuel; Carbon dioxide; Carbon capture; Carbon monoxide; Oxygen combus- tion techniques that can accommodate capture and sequestration of carbon dioxide. This can

  5. Photocatalytic reduction of methylene blue by TiO2 nanotube arrays: effects of TiO2 crystalline phase

    E-Print Network [OSTI]

    Kang, Xiongwu; Chen, Shaowei

    2010-01-01

    N, Pelizzetti E (1989) Photocatalysis: fundamentals andPhotoelectrochemistry, photocatalysis, and photoreactors:performance. Introduction Photocatalysis of a chemical

  6. The DMSO-Li2O2 Interface in the Rechargeable Li-O2 Battery Cathode...

    Office of Scientific and Technical Information (OSTI)

    Research Org: Energy Frontier Research Centers (EFRC); Nanostructures for Electrical Energy Storage (NEES) Sponsoring Org: USDOE SC Office of Basic Energy Sciences (SC-22)...

  7. The DMSO-Li2O2 Interface in the Rechargeable Li-O2 Battery Cathode:

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference)Feedback SystemGimbaledM-PACEConnectTheoretical and Experimental

  8. Transforming subatomic research with IoT From atoms to quarks, to the cosmos and the nature of dark energy --SLAC National

    E-Print Network [OSTI]

    Chaudhuri, Surajit

    clean energy. Research conducted there has revealed intimate details of atoms, led to the discovery States Department of Energy, the SLAC National Accelerator Laboratory is a 50-year-old, two-mile long energy -- SLAC National Accelerator Laboratory explores the origins of the universe. Nestled in the hills

  9. iCOMOT -A Toolset for Managing IoT Cloud Hong-Linh Truong, Georgiana Copil, Schahram Dustdar, Duc-Hung Le, Daniel Moldovan, Stefan Nastic

    E-Print Network [OSTI]

    Dustdar, Schahram

    configurations. We will demonstrate our iCOMOT with a real-world predictive maintenance case study. 1 application domains, such as smart cities, building management, and logistics. In developing and operating Io scenarios for smart city management in the context of predic- tive maintenance problems. The rest

  10. A Comparative Study of the Water Gas Shift Reaction Over Platinum Catalysts Supported on CeO2, TiO2 and Ce-Modified TiO2

    SciTech Connect (OSTI)

    Gonzalez, I.; Navarro, R; Wen, W; Marinkovic, N; Rodriguez, J; Rosa, F; Fierro, J

    2010-01-01

    WGS reaction has been investigated on catalysts based on platinum supported over CeO{sub 2}, TiO{sub 2} and Ce-modified TiO{sub 2}. XPS and XANES analyses performed on calcined catalysts revealed a close contact between Pt precursors and cerium species on CeO{sub 2} and Ce-modified TiO{sub 2} supports. TPR results corroborate the intimate contact between Pt and cerium entities in the Pt/Ce-TiO{sub 2} catalyst that facilitates the reducibility of the support at low temperatures while the Ce-O-Ti surface interactions established in the Ce-modified TiO{sub 2} support decreases the reduction of TiO{sub 2} at high temperature. The changes in the support reducibility leads to significant differences in the WGS activity of the studied catalysts. Pt supported on Ce-modified TiO{sub 2} support exhibits better activity than those corresponding to individual CeO{sub 2} and TiO{sub 2}-supported catalysts. Additionally, the Ce-TiO{sub 2}-supported catalyst displays better stability at reaction temperatures higher than 573 K that observed on pure TiO{sub 2}-supported counterpart. Activity measurements, when coupled with the physicochemical characterization of catalysts suggest that the modifications in the surface reducibility of the support play an essential role in the enhancement of activity and stability observed when Pt is supported on the Ce-modified TiO{sub 2} substrate.

  11. Synthesis of hectorite-TiO2 and kaolinite-TiO2 nanocomposites with photocatalytic activity for the degradation of model air pollutants

    SciTech Connect (OSTI)

    Destaillats, Hugo; Kibanova, D.; Trejo, M.; Destaillats, H.; Cervini-Silva, J.

    2008-03-01

    We studied the synthesis and photocatalytic activity of small-sized TiO{sub 2} supported on hectorite and kaolinite. Deposition of TiO{sub 2} on the clay mineral surface was conducted by using a sol-gel method with titanium isopropoxide as precursor. Anatase TiO{sub 2} particles formation was achieved by hydrothermal treatment at 180 C. Material characterization was conducted using XRD, SEM, XPS, ICP-OES, BET and porosimetry analysis. Efficiency in synthesizing clay-TiO{sub 2} composites depended strongly on the clay mineral structure. Incorporation of anatase in hectorite, an expandable clay mineral, was found to be very significant (> 36 wt.% Ti) and to be followed by important structural changes at the clay mineral surface. Instead, no major structural modifications of the clay were observed for kaolinite-TiO{sub 2}, as compared with the untreated material. Photocatalytic performance of clay-TiO{sub 2} composites was evaluated with ATR-FTIR following the oxidation of adsorbed toluene and d-limonene, two model air pollutants. In either case, the photocatalytic removal efficiency of these hydrophobic substrates by the synthesized clay-TiO{sub 2} composites was comparable to that observed using pure commercial TiO{sub 2} (Degussa P25).

  12. Studies of the Excited State Dynamics of N2O2 by Dissociative Photodetachment of N2O2 Runjun Li and Robert E. Continetti*

    E-Print Network [OSTI]

    Continetti, Robert E.

    to their potential importance as intermediates in catalytic reduction processes1,2 and as potential energetic materials.3 The weakly bound ground- state dimer of nitric oxide, (NO)2, has been extensively investigated The oxides of nitrogen play an important role in atmospheric chemistry and have received attention owing

  13. Design and Fabrication of In-Reactor Experiment to Measure Tritium Release and Speciation from LiAlO2 and LiAlO2/Zr Cermets

    Broader source: Energy.gov [DOE]

    Presentation from the 32nd Tritium Focus Group Meeting held in Germantown, Maryland on April 23-25, 2013.

  14. Recovery of 238PuO2 by Molten Salt Oxidation Processing of 238PuO2 Contaminated Combustibles (Part II)

    SciTech Connect (OSTI)

    Remerowski, Mary Lynn; Dozhier, C.; Krenek, K.; VanPelt, C. E.; Reimus, M. A.; Spengler, D.; Matonic, J.; Garcia, L.; Rios, E.; Sandoval, F.; Herman, D.; Hart, R.; Ewing, B.; Lovato, M.; Romero, J. P. [Los Alamos National Laboratory, Pu-238 Science and Engineering, NMT-9, M/S E502, Los Alamos, NM 87544 (United States)

    2005-02-06

    Pu-238 heat sources are used to fuel radioisotope thermoelectric generators (RTG) used in space missions. The demand for this fuel is increasing, yet there are currently no domestic sources of this material. Much of the fuel is material reprocessed from other sources. One rich source of Pu-238 residual material is that from contaminated combustible materials, such as cheesecloth, ion exchange resins and plastics. From both waste minimization and production efficiency standpoints, the best solution is to recover this material. One way to accomplish separation of the organic component from these residues is a flameless oxidation process using molten salt as the matrix for the breakdown of the organic to carbon dioxide and water. The plutonium is retained in the salt, and can be recovered by dissolution of the carbonate salt in an aqueous solution, leaving the insoluble oxide behind. Further aqueous scrap recovery processing is used to purify the plutonium oxide. Recovery of the plutonium from contaminated combustibles achieves two important goals. First, it increases the inventory of Pu-238 available for heat source fabrication. Second, it is a significant waste minimization process. Because of its thermal activity (0.567 W per gram), combustibles must be packaged for disposition with much lower amounts of Pu-238 per drum than other waste types. Specifically, cheesecloth residues in the form of pyrolyzed ash (for stabilization) are being stored for eventual recovery of the plutonium.

  15. Spatial Profiles in RuO2-CuO-NaCl/SiO2 Packed-Bed Propylene Epoxidation Reactors

    E-Print Network [OSTI]

    Senkan, Selim M.

    (AA), and formaldehyde (FA), together with deep oxidation products of CO and CO2. Earlier research of a large variety of valuable consumer products such as polyurethane foams, propylene glycol, cosmetics

  16. SnO2-CuO-NaCl/SiO2 Catalysts for Propylene Epoxidation Aaron Miller, Bahman Zohour, Anusorn Seubsai, Daniel Noon, and Selim Senkan*

    E-Print Network [OSTI]

    Senkan, Selim M.

    conversion of 1% at 250 °C and 1 bar. A product shift toward CO2, found to occur during continuous operation of propylene and molecular oxygen over a solid catalyst can also result in combustion to CO2, as well foams, insecticides, antifreeze, and cosmetics.1,2 Propylene oxide production consumes over 10

  17. 2+/TiO2-Codoped Zeolites: Synthesis, Characterization, and the Role of TiO2 in Electron Transfer Photocatalysis

    E-Print Network [OSTI]

    Turro, Claudia

    Transfer Photocatalysis Stefan H. Bossmann,*, Claudia Turro, Claudia Schnabel, Megh Raj Pokhrel, Leon M, such an effective electron-transfer relay was missing in zeolite photocatalysis, and therefore, the possible

  18. Synthesis of hectorite-TiO2 and kaolinite-TiO2 nanocomposites with photocatalytic activity for the degradation of model air pollutants

    E-Print Network [OSTI]

    Kibanova, D.

    2008-01-01

    of semiconductor photocatalysis. Chem. Rev. 95, 69-96.clay on adsorption and photocatalysis of gaseous molecules2 (Degussa P25). Keywords: photocatalysis, clays, hectorite,

  19. Laser diagnostics of pulverized coal combustion in O_2/N_2 and O_2/CO_2 conditions: velocity and scalar field measurements

    E-Print Network [OSTI]

    Balusamy, Saravanan; Kamal, M. Mustafa; Lowe, Steven M.; Tian, Bo; Gao, Yi; Hochgreb, Simone

    2015-05-13

    .com emissions (Metz et al. 2005; IEA 2012). Increasing demand for power, especially in developing countries, will lead to a further increase in CO2 emissions and other harmful pollutants. To address the problem, several carbon capture and storage (CCS... Cerrejon coal Proximate analysis wt% Volatile matter 34.80 Fixed carbon 50.80 Moisture 5.80 Ash 8.60 Ultimate analysis wt% Carbon 69.20 Hydrogen 4.40 Oxygen 9.98 Nitrogen 1.42 Sulfur 0.58 Sieve pitch (?m) Cum. mass% Mass% 500 100 10 210 90 28 150 62 12 75...

  20. The Nature of the Surface Species Formed on Au/TiO2 during the Reaction of H2 and O2: An Inelastic Neutron Scattering Study

    E-Print Network [OSTI]

    Goodman, Wayne

    Neutron Scattering Study Chinta Sivadinarayana, Tushar V. Choudhary, Luke L. Daemen, Juergen Eckert of obvious interest for understanding this process. Vibrational spectroscopy by inelastic neutron scattering

  1. Efficient preparation of nanocrystalline anatase TiO2 and V/TiO2 thin layers using microwave drying and/or microwave calcination technique

    E-Print Network [OSTI]

    Cirkva, Vladimir

    in microwave field were done in the same manner, by using an IR pyrometer in the microwave oven and monitoring many important applications, including, among others, dye-sensitized solar cells [1] or photocatalytic

  2. Preparation and Characterization of Au-ZrO2-SiO2 Nanocomposite Spheres and Their Application in Enrichment and Detection of Organophosphorus Agents

    SciTech Connect (OSTI)

    Yang, Yuqi; Tu, Haiyang; Zhang, Aidong; Du, Dan; Lin, Yuehe

    2012-03-01

    Au-ZrO{sub 2}-SiO{sub 2} nanocomposite spheres were synthesized and used as selective sorbents for the solid-phase extraction (SPE) of orananophosphorous agents. A non-enzymatic electrochemical sensor based on an Au-ZrO{sub 2}-SiO{sub 2} modified electrode was developed for selective detection of orananophosphorous pesticides (OPs). The Au-ZrO{sub 2}-SiO{sub 2} nanocomposite spheres were synthesized by hydrolysis and condensation of zirconia n-butoxide (TBOZ) on the surface of SiO{sub 2} spheres and then introduction of gold nanoparticles on the surface. Transmission electron microscope and X-ray photoelectron spectroscopy were performed to characterize the formation of the nanocomposite sphere. Fast extraction of OP was achieved by Au-ZrO{sub 2}-SiO{sub 2} modified electrode within 5 min via the specific affinity between zirconia and phosphoric group. The assay yields a broad concentration range of paraoxon-ethyl from 1.0 to 500 ng/mL{sup -1} with a detection limit 0.5 ng/mL{sup -1}. This selective and sensitive method holds great promise for the enrichment and detection of OPs.

  3. Radiation induced cavity formation and gold precipitation at the interfaces of a ZrO2/SiO2/Si heterostructure

    SciTech Connect (OSTI)

    Edmondson, Philip D; Wang, Chongmin; Zhu, Zihua; Namavar, Fereydoon; Weber, William J; Zhang, Yanwen

    2011-01-01

    Thin films nano-crystalline zirconia of ~ 300 nm thick were deposited on Si substrate, and the samples were irradiated with 2 MeV Au+ ions at temperatures of 160 and 400 K, up to fluences of 35 displacements per atom. The films were then studied using glancing incidence x-ray diffraction, Rutherford backscattering, secondary ion mass spectroscopy and transmission electron microscopy. During the irradiation, cavities were observed to form at the zirconia/silicon interface. The morphology of the cavities was found to be related to the damage state of the underlying Si substrate. Elongated cavities were observed when the substrate is heavily damaged but not amorphized; however, when the substrate is rendered amorphous, the cavities become spherical. As the ion dose increases, the cavities then act as efficient gettering sites for the Au. The concentration of oxygen within the cavities determines the order in which the cavities getter. Following complete filling of the cavities, the interface acts as the secondary gettering site for the Au. The Au precipitates are determined to be elemental in nature due to the high binding free energy for the formation of Au-silicides.

  4. Phases in ceria-zirconia binary oxide (1-x)CeO2-xZrO2 nanoparticles: the size effects

    SciTech Connect (OSTI)

    Zhang,F.; Chen, C.; Hanson, J.; Herman, I.; Chan, S.

    2006-01-01

    The phases of ceria-zirconia nanoparticles observed in air are studied as a function of particle size and composition by X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. The emergence of two tetragonal phases t{prime}{prime} and t monotonically moves toward higher zirconia concentrations with decreasing particle size. A smaller particle size increases the solubility of zirconia in cubic ceria, while higher zirconia content in ceria stabilizes against coarsening. In particular, the cubic Ce{sub 1-x}Zr{sub x}O{sub 2-y} is persistent and is 8% in phase amount even at 90% zirconia with 33 nm crystal size. Neither the monoclinic phase m nor the tetragonal phase t{prime} is observed in the present nanoparticles (<40 nm). The effectiveness of these nanoparticles as oxygen source-and-sink in catalytic support is largely due to the persistence of the cubic and the t{prime}{prime} phases.

  5. Solid-Solution Nanoparticles: Use of a Nonhydrolytic Sol-Gel Synthesis To Prepare HfO2 and HfxZr1-xO2

    E-Print Network [OSTI]

    and Applied Mathematics, and Materials Research Science and Engineering Center, Columbia University, New York ( hafnia 30, zirconia 25), high melting points (2758 and 2700 °C, respectively), and great chemical. Hafnia and zirconia in the bulk can each adopt three different, albeit related, crystal structures

  6. PVP-Assisted ZrO2 coating on LiMn2O4 spinel cathode nanoparticles prepared by MnO2 nanowire templates

    E-Print Network [OSTI]

    Cho, Jaephil

    [5­10]. Although Li-ion batteries are attractive power-storage devices that have high energy density dur- ing storage and cycling at elevated temperatures [1,2]. Capacity fade upon cycling depends active material. However, enhanced rate capabilities can be achieved in nanostructured materials because

  7. Theoretical study of small clusters of indium oxide: InO, In2O; InO2; In2O2 Saikat Mukhopadhyay a

    E-Print Network [OSTI]

    Pandey, Ravi

    ) is being used in devices like liquid crystal display (LCD) plasma, electromagnetic and organic light-emitting diode (OLED) displays. Recently, chro- mium doped In2O3 (e.g. In2Ã?xCrxO3) has been reported as a mag

  8. Formation of Radioactive Citrulline During Photosynthetic C14O2-Fixation by Blue-Green Algae

    E-Print Network [OSTI]

    Linko, Pekka; Holm-Hansen, O.; Bassham, J.A.; Calvin, M.

    1956-01-01

    ClTRULLlNE BY BLUE-GREEN ALGAE TWO-WEEK LOAN COPY This is aC~~O~-FIXATION BLUE-GREEN ALGAE Pekka Linko, 0. Holm-Hansen,C~~O~-FIXATION BLUE-GREEN ALGAE BY Pelcka Linlc~,'~ Holm-

  9. Author's personal copy Graphene and nanostructured MnO2 composite

    E-Print Network [OSTI]

    Qin, Lu-Chang

    , and electrical conductivity. In this paper, graphene is explored as a platform for energy storage devices energy saving devices. They can provide a huge amount of en- ergy in a short period of time, making themA with an energy density of 11.4 Wh/kg and 25.8 kW/kg of power density. This work suggests that our graphene

  10. Materials Data on MnO2 (SG:166) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  11. Electron-beam-induced deformations of SiO2 nanostructures A. J. Storma

    E-Print Network [OSTI]

    Dekker, Cees

    that metallic electrodes with nanometer spacing can be made by electroplating. During the electroplating

  12. Arrays of SiO(2) Substrate-Free Micromechanical Uncooled THz...

    Office of Scientific and Technical Information (OSTI)

    process flow that involved three photolithography steps and no wet etching. The noise equivalent temperature difference intrinsic to the detectors fabricated during this...

  13. Materials Data on Fe3(O2F)2 (SG:1) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  14. Materials Data on RbO2 (SG:139) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  15. Materials Data on SiO2 (SG:227) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  16. Design of a MidO2PL Database Replication Protocol in a Middleware Architecture

    E-Print Network [OSTI]

    Muñoz, Francesc

    Management System (DBMS) internals. However, it introduces an additional overhead that may lead to poor by the modification of the DBMS internals, such as [CL91, BHG87, KPA+03]. This approach presents good performance but lacks of compatibility between several DBMS vendors. The alternative approach is to deploy a middleware

  17. Artificial Photosynthesis on TiO2-Passivated InP Nanopillars

    E-Print Network [OSTI]

    2015-01-01

    Engineering, University of Southern California, Los Angeles, California 90089, United States Department of Chemistry and Biochemistry, ?

  18. Retail of the future : O2O or O&O?

    E-Print Network [OSTI]

    Somani, Vaibhav, S.M. Massachusetts Institute of Technology

    2015-01-01

    Retail industry has transformed in the first decade of this century and new trends continue to disrupt it. Rise of the online channel has pushed the entire retail industry to innovate and think of novel ways to attract and ...

  19. High-pressure structure of half-metallic CrO2 B. R. Maddox

    E-Print Network [OSTI]

    Pickett, Warren

    measurable discontinuity in volume, but is accompanied by an apparent increase in compressibility. Raman data. 1 , one of the most fundamental building blocks of co- valently bonded network structures found in hard materials and earth minerals like stishovite. Larger metal ions i.e., M=W, Re, Mo, etc. , however

  20. Materials Data on Sr(CuO)2 (SG:141) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  1. Materials Data on Sr(FeO2)2 (SG:14) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  2. Materials Data on Sr(BiO2)2 (SG:12) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  3. Materials Data on Sr(GaO2)2 (SG:14) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  4. Materials Data on Sr(Ag3O2)2 (SG:52) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  5. PHOTOVOLTAIC PROPERTIES OF METAL-MEROCYANINE-TiO2 SANDWICH CELLS

    E-Print Network [OSTI]

    Skotheim, Terje Asbjorn

    2011-01-01

    used in making the photovoltaic cells. Figure 3. Diagram ofused in making the photovoltaic cells. HO HO ,5 di -t rt.organic compounds in photovoltaic cells. It lies more in the

  6. Structural and rheological aspect of mesoporous nanocrystalline TiO2 synthesized via solgel process

    E-Print Network [OSTI]

    Gulari, Erdogan

    ­gel process N. Phonthammachai a , T. Chairassameewong a , E. Gulari b , A.M. Jamieson c , S. Wongkasemjit a,* a The Petroleum and Petrochemical College, Chulalongkorn University, Phya Thai Road, Bangkok 10330, Thailand b glycolate; Titania; Rheology; Sol­gel process and viscoelastic properties 1. Introduction Titanium dioxide

  7. Photosynthesis Respiration CH2O + O2 CO2 + H2O

    E-Print Network [OSTI]

    - transports energy ATP and water are readily available anywhere in the cell - acts as a "rechargeable battery Bacteria dinner time What can you do with ATP? 2005 New York City Marathon | Photo by sabrebelle courtesy

  8. PHOTOVOLTAIC PROPERTIES OF METAL-MEROCYANINE-TiO2 SANDWICH CELLS

    E-Print Network [OSTI]

    Skotheim, Terje Asbjorn

    2011-01-01

    yields the thermal activation energy of photoconductance Itsstates in the gap. Thermal activation out of the bound

  9. Pressureless nanoimprinting of anatase TiO2 precursor films Dustin A. Richmond

    E-Print Network [OSTI]

    Cao, Guozhong

    ethanol, as a solvent. The use of an incompletely cross-linked very soft polydimethylsiloxane mold the observed substrate-constrained shrinkage of pillars and lines ridges during annealing. © 2011 American polydimethyl- siloxane PDMS mold.10 A similar chemistry was recently employed by Yoon et al., who demonstrated

  10. Synthesis and Characterization of MnO2-Based Mixed Oxides as Supercapacitors

    E-Print Network [OSTI]

    Popov, Branko N.

    difference, the stability over large potential range is considered to be a crucial factor for super- capacitors. In this study an attempt was made to synthesize at ambient tem- perature new mixed oxides based

  11. Mechanism of Methane Chemical Looping Combustion with Hematite Promoted with CeO2

    SciTech Connect (OSTI)

    Miller, Duane D.; Siriwardane, Ranjani

    2013-08-01

    Chemical looping combustion (CLC) is a promising technology for fossil fuel combustion that produces sequestration-ready CO{sub 2} stream, reducing the energy penalty of CO{sub 2} separation from flue gases. An effective oxygen carrier for CLC will readily react with the fuel gas and will be reoxidized upon contact with oxygen. This study investigated the development of a CeO{sub 2}-promoted Fe{sub 2}O{sub 3}?hematite oxygen carrier suitable for the methane CLC process. Composition of CeO{sub 2} is between 5 and 25 wt % and is lower than what is generally used for supports in Fe{sub 2}O{sub 3} carrier preparations. The incorporation of CeO{sub 2} to the natural ore hematite strongly modifies the reduction behavior in comparison to that of CeO{sub 2} and hematite alone. Temperature-programmed reaction studies revealed that the addition of even 5 wt % CeO{sub 2} enhances the reaction capacity of the Fe{sub 2}O{sub 3} oxygen carrier by promoting the decomposition and partial oxidation of methane. Fixed-bed reactor data showed that the 5 wt % cerium oxides with 95 wt % iron oxide produce 2 times as much carbon dioxide in comparison to the sum of carbon dioxide produced when the oxides were tested separately. This effect is likely due to the reaction of CeO{sub 2} with methane forming intermediates, which are reactive for extracting oxygen from Fe{sub 2}O{sub 3} at a considerably faster rate than the rate of the direct reaction of Fe{sub 2}O{sub 3} with methane. These studies reveal that 5 wt % CeO{sub 2}/Fe{sub 2}O{sub 3} gives stable conversions over 15 reduction/oxidation cycles. Lab-scale reactor studies (pulsed mode) suggest the methane reacts initially with CeO{sub 2} lattice oxygen to form partial oxidation products (CO + H{sub 2}), which continue to react with oxygen from neighboring Fe{sub 2}O{sub 3}, leading to its complete oxidation to form CO{sub 2}. The reduced cerium oxide promotes the methane decomposition reaction to form C + H{sub 2}, which continue to react with Fe{sub 2}O{sub 3}/Fe{sub 3}O{sub 4} to form CO/CO{sub 2} and H{sub 2}O. This mechanism is supported by the characterization studies, which also suggest that the formation of carbonaceous intermediates may affect the reaction rate and selectivity of the oxygen carrier.

  12. Growth Kinetics and Modeling of Direct Oxynitride Growth with NO-O2 Gas Mixtures

    SciTech Connect (OSTI)

    Everist, Sarah; Nelson, Jerry; Sharangpani, Rahul; Smith, Paul Martin; Tay, Sing-Pin; Thakur, Randhir

    1999-05-03

    We have modeled growth kinetics of oxynitrides grown in NO-O2 gas mixtures from first principles using modified Deal-Grove equations. Retardation of oxygen diffusion through the nitrided dielectric was assumed to be the dominant growth-limiting step. The model was validated against experimentally obtained curves with good agreement. Excellent uniformity, which exceeded expected walues, was observed.

  13. Monoethanolamine Degradation: O2 Mass Transfer Effects under CO2 Capture Conditions

    E-Print Network [OSTI]

    Rochelle, Gary T.

    of MEA, is then sent through a counter- current heat exchanger, where it is preheated by the lean amine sequestered. The hot lean amine solution, R 0.15, passes through the counter-current heat exchanger where widely used solvent. In this type of process, shown in Figure 1, the flue gas is counter

  14. Absorption Properties of Hybrid SnO2 Nanocrystal-Carbon Nanotube Structures

    E-Print Network [OSTI]

    Chen, Junhong

    applications such as in gas sensors,1,2 solar energy conversion devices,3 and transparent electrodes.4 and the size-dependent elec- tronic and optical properties (variable energy band gaps) of the semiconducting and molecular computers,20 by taking advantage of unique properties of CNTs, which include ballistic electronic

  15. Chemistry of Tantalum Clusters in Solution And on SiO(2) Supports: Analogies And Contrasts

    SciTech Connect (OSTI)

    Nemana, S.; Okamoto, N.L.; Browning, N.D.; Gates, B.C.

    2009-06-03

    Tantalum clusters have been synthesized from Ta(CH{sub 2}Ph){sub 5} on the surface of porous fumed SiO{sub 2}. When these clusters are small, incorporating, on average, several Ta atoms, their chemistry is similar to that of molecular tantalum clusters (and other early transition-metal) clusters. For example, The Ta-Ta bonds in these small supported clusters have been characterized by extended X-ray absorption fine structure (EXAFS), IR, and UV-vis spectroscopy, being similar to those in molecular analogues. The redox reactions of the supported clusters, characterized by X-ray absorption near-edge structure, are analogous to those of early transition-metal clusters in solution. In contrast to the largest of these clusters in solution and in the solid state, those supported on SiO{sub 2} are raftlike, facilitating the substantial metal-support-oxygen bonding that is evident in the EXAFS spectra. Samples consisting of tantalum clusters on SiO{sub 2} catalyze alkane disproportionation and the conversion of methane with n-butane to give other alkanes, but catalytic properties of analogous clusters in solution have barely been explored.

  16. Materials Data on Rb2NiO2 (SG:139) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  17. Materials Data on S(ClO)2 (SG:43) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  18. PHOTOVOLTAIC PROPERTIES OF METAL-MEROCYANINE-TiO2 SANDWICH CELLS

    E-Print Network [OSTI]

    Skotheim, Terje Asbjorn

    2011-01-01

    67 3.6 Photovoltaic Action Spectrum . . . . 3.7dye used in making the photovoltaic cells. Figure 3. Diagramused in making the photovoltaic cells. HO HO ,5 di -t rt.

  19. Materials Data on LiMoO2 (SG:58) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  20. Materials Data on Na(CoO2)3 (SG:1) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  1. Effect of fasting on the V O2-fh relationship in king penguins, Aptenodytes patagonicus

    E-Print Network [OSTI]

    Fahlman, Andreas

    15 2TT, United Kingdom; 2 Centre d'Ecologie et Physiologie Energe´tiques, CNRS, 67087 Strasbourg Cedex 02; and 4 Physiologie des Re´gulations Energe´tiques, Cellulaires, et Mole´culaires, CNRS

  2. Surface-structure sensitivity of CeO2 nanocrystals in photocatalysis...

    Office of Scientific and Technical Information (OSTI)

    heterogeneous (photo)catalysis. In this study, using aberration-corrected scanning transmission electron microscopy (STEM), the atomic surface structures of well-defined...

  3. HPCERC2000-017 Point Defects in Si/SiO2

    E-Print Network [OSTI]

    Maccabe, Barney

    , Kirtland AFB, New Mexico H.A. Kurtz The University of Memphis, TN Department of Chemistry A. C. Pineda The University of New Mexico ­ HPCERC Albuquerque High Performance Computing Center #12;Disclaimer The High and communication at the University of New Mexico (UNM). HPCERC is committed to innovative research in computational

  4. Photocatalytic Degradation of VOC's by TOTO's Hydrotect (TiO2 Impregnated) Surfaces

    E-Print Network [OSTI]

    Bergin, Mike

    and Environmental Engineering Georgia Institute of Technology December 9, 2009 #12;2 Executive Summary A variety strippers, aerosol spray cans, wall paints, carburetor cleaners and air wind shield products use methanol

  5. ?-NaMnO2: a High Performance Cathode for Sodium-Ion Batteries

    E-Print Network [OSTI]

    Billaud, Juliette; Clément, Raphaële J.; Armstrong, A. Robert; Canales-Vázquez, Jesús; Rozier, Patrick; Grey, Clare P.; Bruce, Peter G.

    2014-11-14

    Na RF pulses were assumed to be selective for the 23Na central transition. 2.8. Chemical Analyses. Chemical analyses were per- formed by Inductively Coupled Plasma (ICP) emission spectroscopy. 3. RESULTS AND DISCUSSION 3.1. Electrochemistry... collapses when Na is extracted, and is then recovered when Na is reinserted, but with an increase in the proportion of twin boundaries. Despite these changes the electrochemistry is very stable on cycling, as shown in Figure 2. This is in contrast...

  6. Conformal MnO2 Electrodeposition Onto Defect-Free Graphitic Carbons

    E-Print Network [OSTI]

    Collins, Philip G

    2011-01-01

    I. Perez et al. / Electrochemistry Communications 13 (2011)Electrochemistry Communications 13 (2011) 590–592available at ScienceDirect Electrochemistry Communications j

  7. 2H2O O2 + 4H+ + 4e b H2O OH + H+

    E-Print Network [OSTI]

    Hendry, Andrew

    2 R2 R2 Ruthenium 'blue dimer' + Figure 1 | Catalytic water oxidation. Photosynthesis is fuelled by the conversion of water into oxygen and hydrogen. a, In the first part of this process, known as water oxidation, water is converted into oxygen, four protons (H+ ) and four electrons (e­ ). b, Oxidation by the removal

  8. Tuning the Optical Properties of Mesoporous TiO2 Films by Nanoscale Engineering

    SciTech Connect (OSTI)

    Schwenzer, Birgit; Wang, Liang; Swensen, James S.; Padmaperuma, Asanga B.; Silverman, Gary; Korotkov, Roman; Gaspar, Daniel J.

    2012-07-03

    Introducing mesoscale pores into spincoated titanium dioxide films, prepared by spincoating different sol-gel precursor solutions on silicon substrates and subsequent annealing at 350 C, 400 C or 450 C, respectively, affects several optical properties of the material. The change in refractive index observed for different mesoporous anatase films directly correlates with changes in pore size, but is also in a more complex manner influenced by the film thickness and the density of pores within the films. Additionally, the band gap of the films is blueshifted by the stress the introduction of pores exerts on the inorganic matrix. The differently sized pores were templated by Pluronic{reg_sign} block copolymers in the solgel solutions and tuned by employing different annealing temperatures for the film preparation. This study focused on elucidating the effect different templating materials (F127 and P123) have on the pore size of the final mesoporous titania film, and on understanding the relation of varying polymer concentration (taking P123 as an example) in the sol-gel solution to the pore concentration and size in the resultant titania film. Titania thin film samples or corresponding titanium dioxide powders were characterized by X-ray diffraction, nitrogen adsorption, ellipsometery, UV/Vis spectrometry and other techniques to understand the interplay between mesoporosity and optical properties.

  9. Materials Data on HfO2 (SG:61) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  10. Supporting Online Materials Electron Microscopy Observation of TiO2 Nanocrystal Evolution in High-

    E-Print Network [OSTI]

    Wang, Xudong

    was allowed to cool down naturally without changing the system pressure and carrier gas flow. (3) Growth of Si of gaseous TiCl4 and H2O vapors were controlled by solenoid valves and adjusted by fine tuning the precursor as the carrier gas, which provided a background pressure of 2.7 Torr. The chamber temperature was maintained

  11. SESAME 96170, a solid-liquid equation of state for CeO2

    SciTech Connect (OSTI)

    Chisolm, Eric D.

    2014-05-02

    I describe an equation of state (EOS) for the low-pressure solid phase and liquid phase of cerium (IV) oxide, CeO2. The models and parameters used to calculate the EOS are presented in detail, and I compare with data for the full-density crystal. Hugoniot data are available only for high-porosity powders, and I discuss difficulties in comparing with such data. I have constructed SESAME 96170, an EOS for cerium (IV) oxide that includes the ambient solid and liquid phases. The EOS extends over the full standard SESAME range, but should not be used at low temperatures and high densities because of the lack of a high-pressure solid phase. I have described the models used to compute the three terms of the EOS (cold curve, nuclear, and thermal electronic), and I have given the parameters used in the models. They were determined by comparison with experimental data at P = 1 atm, including the constant-pressure specific heat, coefficient of thermal expansion, and melting and boiling points. The EOS compares well with data in its intended range of validity, but the presence of high-frequency optical modes in its phonon spectrum limits the agreement of our models with thermal data. The next step is to construct a multiphase EOS that includes the low- and high-pressure solid phases and the liquid. The DAC data from Duclos will most strongly constrain the parameters of the high-pressure solid. A remaining issue is the comparison of the crystal-density EOS with experimental Hugoniot data, which are taken at much lower initial data because the samples are porous powders. A satisfactory means of modeling porosity, allowing comparison of theory and experiment, has not yet been produced.

  12. Electrophoretic Study of the SnO2/Aqueous Solution Interface up to 260 degrees C.

    SciTech Connect (OSTI)

    Rodriguez-Santiago, V; Fedkin, Mark V.; Wesolowski, David J

    2009-07-01

    An electrophoresis cell developed in our laboratory was utilized to determine the zeta potential at the SnO{sub 2} (cassiterite)/aqueous solution (10{sup -3} mol kg{sup -1} NaCl) interface over the temperature range from 25 to 260 C. Experimental techniques and methods for the calculation of zeta potential at elevated temperature are described. From the obtained zeta potential data as a function of pH, the isoelectric points (IEPs) of SnO{sub 2} were obtained for the first time. From these IEP values, the standard thermodynamic functions were calculated for the protonation-deprotonation equilibrium at the SnO{sub 2} surface, using the 1-pK surface complexation model. It was found that the IEP values for SnO{sub 2} decrease with increasing temperature, and this behavior is compared to the predicted values by the multisite complexation (MUSIC) model and other semitheoretical treatments, and were found to be in excellent agreement.

  13. Ultrafast visualization of crystallization and grain growth in shock-compressed SiO2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gleason, A. E.; Bolme, C. A.; Lee, H. J.; Nagler, B.; Galtier, E.; Milathianaki, D.; Hawreliak, J.; Kraus, R. G.; Eggert, J. H.; Fratanduono, D. E.; et al

    2015-09-04

    Pressure- and temperature-induced phase transitions have been studied for more than a century but very little is known about the non-equilibrium processes by which the atoms rearrange. Shock compression generates a nearly instantaneous propagating high-pressure/temperature condition while in situ X-ray diffraction (XRD) probes the time-dependent atomic arrangement. Here we present in situ pump–probe XRD measurements on shock-compressed fused silica, revealing an amorphous to crystalline high-pressure stishovite phase transition. Using the size broadening of the diffraction peaks, the growth of nanocrystalline stishovite grains is resolved on the nanosecond timescale just after shock compression. At applied pressures above 18 GPa the nuclueationmore »of stishovite appears to be kinetically limited to 1.4±0.4 ns. The functional form of this grain growth suggests homogeneous nucleation and attachment as the growth mechanism. As a result, these are the first observations of crystalline grain growth in the shock front between low- and high-pressure states via XRD.« less

  14. Europium-Doped TiO2 Hollow Nanoshells: Two-Photon Imaging of Cell Binding

    E-Print Network [OSTI]

    Kummel, Andrew C.

    free for functionalization and the core free for payload encapsulation. Amine and holes are produced. These electrons and holes can react with hydroxyl ions or water to produce reactive hydroxyl radicals ·OH and perhydroxyl radicals HO2·. These oxygen species are also highly reactive

  15. PTFE treatment by remote atmospheric Ar/O2 plasmas: a simple reaction scheme model proposal

    E-Print Network [OSTI]

    Carbone, E A D; Keuning, W; van der Mullen, J J A M

    2013-01-01

    Polytetrafluoroethylene (PTFE) samples were treated by a remote atmospheric pressure microwave plasma torch and analyzed by water contact angle (WCA) and X-ray photoelectron spectroscopy (XPS). In the case of pure argon plasma a decrease of WCA is observed meanwhile an increase of hydrophobicity was observed when some oxygen was added to the discharge. The WCA results are correlated to XPS of reference samples and the change of WCA are attributed to changes in roughness of the samples. A simple kinetics scheme for the chemistry on the PTFE surface is proposed to explain the results.

  16. Engineering of a liquid-crystalline aqueous suspension of TiO2 rutile nanorods

    E-Print Network [OSTI]

    Paris-Sud 11, Université de

    , imogolite) Semi-flexible ribbons (V2O5) 2-d sheets (clays, H3Sb3P2O14) Rod-like (boehmite, goethite) or disk.Onsager's predictions ... #12;3 Chimie douce: Mineral synthesis technique comparable to organic polymerization and Synthesis. From Solution to Solid State, Wiley, Chichester 2000. Mineral synthesis: « Chimie douce

  17. The tight junction protein Z O-2 has several functional nuclear export signals

    SciTech Connect (OSTI)

    Gonzalez-Mariscal, Lorenza [Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies (CINVESTAV), Ave. Instituto Politecnico Nacional 2508, Mexico, D.F., 07360 (Mexico)]. E-mail: lorenza@fisio.cinvestav.mx; Ponce, Arturo [Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies (CINVESTAV), Ave. Instituto Politecnico Nacional 2508, Mexico, D.F., 07360 (Mexico); Alarcon, Lourdes [Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies (CINVESTAV), Ave. Instituto Politecnico Nacional 2508, Mexico, D.F., 07360 (Mexico); Jaramillo, Blanca Estela [Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies (CINVESTAV), Ave. Instituto Politecnico Nacional 2508, Mexico, D.F., 07360 (Mexico)

    2006-10-15

    The tight junction (TJ) protein ZO-2 changes its subcellular distribution according to the state of confluency of the culture. Thus in confluent monolayers, it localizes at the TJ region whereas in sparse cultures it concentrates at the nucleus. The canine sequence of ZO-2 displays four putative nuclear export signals (NES), two at the second PDZ domain (NES-0 and NES-1) and the rest at the GK region (NES-2 and NES-3). The functionality of NES-0 and NES-3 was unknown, hence here we have explored it with a nuclear export assay, injecting into the nucleus of MDCK cells peptides corresponding to the ZO-2 NES sequences chemically coupled to ovalbumin. We show that both NES-0 and NES-3 are functional and sensitive to leptomycin B. We also demonstrate that NES-1, previously characterized as a non functional NES, is rendered capable of nuclear export upon the acquisition of a negative charge at its Ser369 residue. Experiments performed injecting at the nucleus WT and mutated ZO-2-GST fusion proteins revealed the need of both NES-0 and NES-1, and NES-2 and NES-3 for attaining an efficient nuclear exit of the respective amino and middle segments of ZO-2. Moreover, the transfection of MDCK cells with full-length ZO-2 revealed that the mutation of any of the NES present in the molecule was sufficient to induce nuclear accumulation of the protein.

  18. Materials Data on LiH3O2 (SG:12) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  19. Materials Data on NaH4BrO2 (SG:14) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  20. Materials Data on H5BrO2 (SG:14) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations