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Title: Synthesis of self-organized TiO{sub 2} nanotube arrays: Microstructural, stereoscopic, and topographic studies

Abstract

In this work, titanium dioxide nanotubes were prepared by using titanium foils via electrochemical anodization in ethylene glycol solutions containing different amounts of water and fluoride in the ranges of 1%–3% and 0.15%–0.5%, respectively, to determine their effects on morphology, optical, and crystalline structure properties. Annealing processes were performed on all samples in the range between 273 and 723 K. Morphology and structure properties of the samples were studied by scanning electron microscopy, X-ray diffraction (XRD), and transmission electron microscopy. Titanium dioxide (TiO{sub 2}) nanotubes, through anodization method, are strongly influenced by conditions, like fluoride concentration and applied voltages. Tube lengths between 2 and 7 μm were obtained, exhibiting different diameters and wall thicknesses. When alternating voltage was applied, the outer surface of the nanotubes exhibited evenly spaced ring-shaped regions, while smooth tubes were observed when constant voltage was applied. Reflection peaks, corresponding to Brookite, Anatase, and Rutile, of TiO{sub 2} phases, were observed from the XRD pattern. These phases were corroborated via μXRD measurements, and the Ti{sub 3}O{sub 5} phase was also observed in detail. Absorption coefficient (α), optical band gap (Eg), and extinction coefficient (ε) of TiO{sub 2} nanotubes were calculated by transmittance spectra in the UV–Vis range. Strong absorptionmore » was noted in the UV region from reflectance and absorbance measurements. A correlation between synthesis parameters and physical properties is presented.« less

Authors:
;  [1]
  1. Department of Physis, Grupo de Materiales Nanoestructurados y sus Aplicaciones, Universidad Nacional de Colombia, Bogotá 11001 (Colombia)
Publication Date:
OSTI Identifier:
22597832
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 120; Journal Issue: 5; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; ANODIZATION; ELECTRIC POTENTIAL; ETHYLENE; FLUORIDES; GLYCOLS; MICROSTRUCTURE; MORPHOLOGY; NANOTUBES; PHYSICAL PROPERTIES; RUTILE; SCANNING ELECTRON MICROSCOPY; SPECTRA; THICKNESS; TITANIUM; TITANIUM OXIDES; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION

Citation Formats

Quiroz, Heiddy P., E-mail: hpquirozg@unal.edu.co, and Dussan, A., E-mail: adussanc@unal.edu.co. Synthesis of self-organized TiO{sub 2} nanotube arrays: Microstructural, stereoscopic, and topographic studies. United States: N. p., 2016. Web. doi:10.1063/1.4958940.
Quiroz, Heiddy P., E-mail: hpquirozg@unal.edu.co, & Dussan, A., E-mail: adussanc@unal.edu.co. Synthesis of self-organized TiO{sub 2} nanotube arrays: Microstructural, stereoscopic, and topographic studies. United States. doi:10.1063/1.4958940.
Quiroz, Heiddy P., E-mail: hpquirozg@unal.edu.co, and Dussan, A., E-mail: adussanc@unal.edu.co. Sun . "Synthesis of self-organized TiO{sub 2} nanotube arrays: Microstructural, stereoscopic, and topographic studies". United States. doi:10.1063/1.4958940.
@article{osti_22597832,
title = {Synthesis of self-organized TiO{sub 2} nanotube arrays: Microstructural, stereoscopic, and topographic studies},
author = {Quiroz, Heiddy P., E-mail: hpquirozg@unal.edu.co and Dussan, A., E-mail: adussanc@unal.edu.co},
abstractNote = {In this work, titanium dioxide nanotubes were prepared by using titanium foils via electrochemical anodization in ethylene glycol solutions containing different amounts of water and fluoride in the ranges of 1%–3% and 0.15%–0.5%, respectively, to determine their effects on morphology, optical, and crystalline structure properties. Annealing processes were performed on all samples in the range between 273 and 723 K. Morphology and structure properties of the samples were studied by scanning electron microscopy, X-ray diffraction (XRD), and transmission electron microscopy. Titanium dioxide (TiO{sub 2}) nanotubes, through anodization method, are strongly influenced by conditions, like fluoride concentration and applied voltages. Tube lengths between 2 and 7 μm were obtained, exhibiting different diameters and wall thicknesses. When alternating voltage was applied, the outer surface of the nanotubes exhibited evenly spaced ring-shaped regions, while smooth tubes were observed when constant voltage was applied. Reflection peaks, corresponding to Brookite, Anatase, and Rutile, of TiO{sub 2} phases, were observed from the XRD pattern. These phases were corroborated via μXRD measurements, and the Ti{sub 3}O{sub 5} phase was also observed in detail. Absorption coefficient (α), optical band gap (Eg), and extinction coefficient (ε) of TiO{sub 2} nanotubes were calculated by transmittance spectra in the UV–Vis range. Strong absorption was noted in the UV region from reflectance and absorbance measurements. A correlation between synthesis parameters and physical properties is presented.},
doi = {10.1063/1.4958940},
journal = {Journal of Applied Physics},
number = 5,
volume = 120,
place = {United States},
year = {Sun Aug 07 00:00:00 EDT 2016},
month = {Sun Aug 07 00:00:00 EDT 2016}
}
  • Graphical abstract: - Highlights: • TiO{sub 2} nanotube sensitized with CoFe{sub 2}O{sub 4} nanocrystals was synthesized by a facile hydrothermal method. • CoFe{sub 2}O{sub 4} nanocrystals were loaded to the outer and inner surface of TiO{sub 2} nanotube. • The CoFe{sub 2}O{sub 4} sensitized TiO{sub 2} nanotube electrode has a strong photoresponse to the light. - Abstract: TiO{sub 2} nanotube arrays sensitized with CoFe{sub 2}O{sub 4} nanocrystals were successfully synthesized via a facile hydrothermal method. The as-prepared sample was studied by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX) tomore » characterize its phase structure, morphology and chemical composition. Enhanced absorption in both UV and visible-light regions was observed for the CoFe{sub 2}O{sub 4} sensitized TiO{sub 2} nanotube arrays. The photocurrent density of CoFe{sub 2}O{sub 4} sensitized TiO{sub 2} nanotube arrays electrode was 30 times as great as that of bare TiO{sub 2} nanotube arrays electrode.« less
  • Highlights: • MnO{sub 2}/TiO{sub 2} nanotube arrays nanocomposites are prepared by electrodeposition. • MnO{sub 2}/TiO{sub 2} exhibits high visible light photocatalytic activity. • The results of XRD show the depositions are attributed to α-MnO{sub 2}. • A photocatalytic mechanism is discussed under visible light irradiation. - Abstract: MnO{sub 2}/TiO{sub 2} nanotube arrays nanocomposite photocatalysts have been synthesized through an electrodeposition method. X-ray powder diffraction analysis and X-ray photoelectron spectroscopy measurements reveal that the products of electrodeposition method are MnO{sub 2}. Scanning electron microscopy measurements suggest that the depositions are deposited on the surface or internal of the nanotube. UV–vis lightmore » absorbance spectra demonstrate the excellent adsorption properties of MnO{sub 2}/TiO{sub 2} over the whole region of visible light, which enables this novel photocatalytic material to possess remarkable activity in the photocatalytic degradation of acid Orange II under visible light radiation. Moreover, a possible photocatalytic mechanism is discussed.« less
  • Via a facile one-step chemical bath deposition route, homogeneously dispersed Mn{sub 3}O{sub 4} nanoparticles have been successfully deposited onto the inner surface of TiO{sub 2} nanotube arrays (TNAs). The content and size of Mn{sub 3}O{sub 4} can be controlled by changing the deposition time. Field emission scanning electron microscopy and transmission electron microscopy analysis reveal the morphologies structures of Mn{sub 3}O{sub 4}/TNAs composites. The crystal-line structures are characterized by the X-ray diffraction patterns and Raman spectra. X-ray photoelectron spectroscopy further confirms the valence states of the sample elements. The electrochemical properties of Mn{sub 3}O{sub 4}/TNAs electrodes are systematically investigated bymore » the combine use of cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The resulting Mn{sub 3}O{sub 4}/TNAs electrode prepared by deposition time of 3 h shows the highest specific capacitance of 570 F g{sup −1} at a current density of 1 A g{sup −1}. And it also shows an excellent long-term cycling stability at a current density of 5 A g{sup −1}, which remaining 91.8% of the initial capacitance after 2000 cycles. Thus this kind of Mn{sub 3}O{sub 4} nanoparticles decorated TNAs may be considered as an alternative promising candidate for high performance supercapacitor electrodes. - Graphical abstract: Mn{sub 3}O{sub 4} nanoparticles have been uniformly deposited onto the inner surfaces of TiO{sub 2} nanotube arrays through a facile one-step chemical bath deposition method. As electrodes for supercapacitors, they exhibit a relatively high specific capacity and excellent cycling stability. - Highlights: • Mn{sub 3}O{sub 4} nanoparticles have been deposited onto TiO{sub 2} nanotube arrays by chemical bath deposition. • The Mn{sub 3}O{sub 4}/TNAs exhibits a highest specific capacitance of 570 F g{sup –1} at a current density of 1 A g{sup –1}. • The Mn{sub 3}O{sub 4}/TNAs electrode shows an excellent cycling stability of 91.8% after 2000 cycles.« less
  • A large clearance TiO{sub 2} nanotube arrays (LTAs) has been synthesized by a not more than 12 h anodization duration and based on this a branched TiO{sub 2} nanotube arrays (BLTs) has been achieved through TiO{sub 2} nanorods branch-like grown on the LTAs. Some key factors and probable mechanisms of the fabrication processes on two novel nanoarchitectures are discussed. Exhilaratingly, it is found that the obtained LTAs has demonstrated large pore diameter and void spaces (pore diameter {approx}350 nm; void spaces {approx}160 nm; and tube length {approx}3.5 {mu}m), and the synthesized hierarchical BLTs, compared with conventional TiO{sub 2} nanotube arrays,more » has shown a much stronger dye absorption performance and an approximately double of the solar cell efficiency (in our case from 1.62% to 3.18% under simulated AM 1.5 conditions). - Graphical Abstract: The schematic diagram of synthesis process for LTAs and BLTs is on the above and the corresponding FESEM images of obtained photoanodes samples are shown below. Highlights: > Large clearance TiO{sub 2} nanotube arrays (LTAs) was synthesized by a fast anodization process of 12 h. > Anodization time of 12 h is just 10% of about 120 h reported in the previous references. > Branch-like TiO{sub 2} nanotube arrays (BLTs) was achieved by growing TiO{sub 2} nanorods on the LTAs. > Obtained BLTs and LTAs show impressive morphology and noticeable improvement of surface area. > BLTs shows about more than 1 times higher solar cell efficiency than that of TiO{sub 2} nanotube arrays.« less
  • Cu{sub 2}O/TiO{sub 2} nanotube heterojunction arrays have been prepared by photoreduction depositing Cu{sub 2}O nanoparticles on TiO{sub 2} nanotube arrays. The heterojunction arrays show uniformly distributed Cu{sub 2}O nanoparticles, and high crystallinity of anatase and cubic from the TiO{sub 2} and Cu{sub 2}O, respectively. The asymmetry of the current-voltage plot for the material reveals that a heterojunction has been formed between TiO{sub 2} and Cu{sub 2}O. Enhanced charge separation efficiency and improved photoconversion capability are confirmed by electrochemical impedance spectroscopy and photocurrent measurement.