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Title: Structure and Formation Mechanism of Black TiO2 Nanoparticles

Journal Article · · ACS Nano
 [1];  [2];  [3];  [3];  [2];  [3];  [2];  [2];  [2];  [2];  [4]
  1. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
  4. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineeringvv; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
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The remarkable properties of black TiO2 are due to its disordered surface shell surrounding a crystalline core. However, the chemical composition and the atomic and electronic structure of the disordered shell and its relationship to the core remain poorly understood. Using advanced transmission electron microscopy methods, we show that the outermost layer of black TiO2 nanoparticles consists of a disordered Ti2O3 shell. The measurements show a transition region that connects the disordered Ti2O3 shell to the perfect rutile core consisting first of four to five monolayers of defective rutile, containing clearly visible Ti interstitial atoms, followed by an ordered reconstruction layer of Ti interstitial atoms. Our data suggest that this reconstructed layer presents a template on which the disordered Ti2O3 layers form by interstitial diffusion of Ti ions. In contrast to recent reports that attribute TiO2 band-gap narrowing to the synergistic action of oxygen vacancies and surface disorder of nonspecific origin, our results point to Ti2O3, which is a narrow-band-gap semiconductor. In conclusion, as a stoichiometric compound of the lower oxidation state Ti3+ it is expected to be a more robust atomic structure than oxygen-deficient TiO2 for preserving and stabilizing Ti3+ surface species that are the key to the enhanced photocatalytic activity of black TiO2.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC05-00OR22725; AC02-05CH11231
OSTI ID:
1324061
Journal Information:
ACS Nano, Vol. 9, Issue 10; ISSN 1936-0851
Publisher:
American Chemical SocietyCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 149 works
Citation information provided by
Web of Science

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Cited By (25)

Highly Conductive Cable-Like Bicomponent Titania Photoanode Approaching Limitation of Electron and Hole Collection journal July 2018
A hybrid composite of rhenium complexes covalently grafted on reduced graphene oxide/hydrogenated TiO2 as an efficient catalyst for CO2 reduction under visible light journal November 2019
Apparatus-dependent sol-gel synthesis of TiO 2 nanoparticles for dye-sensitized solar cells journal December 2019
Recent progress in characterization of the core–shell structure of black titania journal March 2019
Atomic‐Scale Mapping of Impurities in Partially Reduced Hollow TiO 2 Nanowires journal February 2020
Enhancing formaldehyde oxidation on iridium catalysts using hydrogenated TiO 2 supports journal January 2018
Physico-chemical Characterization and Basic Research Principles of Advanced Drug Delivery Nanosystems book January 2017
Electron‐Beam‐Related Studies of Halide Perovskites: Challenges and Opportunities journal February 2020
Controlled Formation of Defective Shell on TiO 2 (001) Facets for Enhanced Photocatalytic CO 2 Reduction journal March 2019
Black N/H-TiO 2 Nanoplates with a Flower-Like Hierarchical Architecture for Photocatalytic Hydrogen Evolution journal August 2016
TiO2 hollow spheres with surface-rich Ti3+ under Pd-catalyzed hydrogenation for improved visible-light photocatalysis journal February 2019
Increasing the optical response of TiO 2 and extending it into the visible region through surface activation with highly stable Cu 5 clusters journal January 2019
Defects Engineering in Photocatalytic Water Splitting Materials journal October 2019
Different Reactivity of Rutile and Anatase TiO 2 Nanoparticles: Synthesis and Surface States of Nanoparticles of Mixed‐Valence Magnéli Oxides journal September 2009
Magnetic Conductive Outer Layer in Oxygen‐Deficient TiO 2 Single Crystals journal April 2019
Progress in Black Titania: A New Material for Advanced Photocatalysis journal June 2016
Black Titania with Nanoscale Helicity journal August 2019
Femtosecond laser-induced transformations in ultra-low expansion glass: Microstructure and local density variations by vibrational spectroscopy journal June 2018
Low pressure bottom-up synthesis of metal@oxide and oxide nanoparticles: control of structure and functional properties journal January 2018
Novel Black BiVO 4 /TiO 2− x Photoanode with Enhanced Photon Absorption and Charge Separation for Efficient and Stable Solar Water Splitting journal June 2019
Atomic‐Scale Mapping of Impurities in Partially Reduced Hollow TiO 2 Nanowires journal February 2020
Mini Review of TiO 2 -Based Multifunctional Nanocomposites for Near-Infrared Light-Responsive Phototherapy journal June 2018
Tuning the Electronic Conductivity in Hydrothermally Grown Rutile TiO2 Nanowires: Effect of Heat Treatment in Different Environments journal September 2017
Tuning the Electronic Conductivity in Hydrothermally Grown Rutile TiO2 Nanowires: Effect of Heat Treatment in Different Environments text January 2017
Glycerol-Mediated Facile Synthesis of Colored Titania Nanoparticles for Visible Light Photodegradation of Phenolic Compounds journal November 2019

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Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
black TiO₂
core−shell structure
nanoparticles
nonstoichiometry
reduced band-gap
TEM characterization