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Influence of Anodization-Electrolyte Aging on the Photocatalytic Activity of TiO(2) Nanotube Arrays

[Image: see text] TiO(2) nanotubular films prepared using the anodic oxidation process applied to various forms of metal titanium are promising materials for photocatalytic applications. However, during successive anodizations in batch-anodization cells, the chemical composition of the NH(4)F- and w...

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Autores principales: Suhadolnik, Luka, Marinko, Živa, Ponikvar-Svet, Maja, Tavčar, Gašper, Kovač, Janez, Čeh, Miran
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2020
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7737329/
https://www.ncbi.nlm.nih.gov/pubmed/33343787
http://dx.doi.org/10.1021/acs.jpcc.9b09522
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author Suhadolnik, Luka
Marinko, Živa
Ponikvar-Svet, Maja
Tavčar, Gašper
Kovač, Janez
Čeh, Miran
author_facet Suhadolnik, Luka
Marinko, Živa
Ponikvar-Svet, Maja
Tavčar, Gašper
Kovač, Janez
Čeh, Miran
author_sort Suhadolnik, Luka
collection PubMed
description [Image: see text] TiO(2) nanotubular films prepared using the anodic oxidation process applied to various forms of metal titanium are promising materials for photocatalytic applications. However, during successive anodizations in batch-anodization cells, the chemical composition of the NH(4)F- and water-based ethylene glycol electrolyte changes with each subsequent anodization, which greatly affects the final photocatalytic properties of the annealed TiO(2) nanotubular films. In the present study, 20 titanium discs (Φ 90 mm) were sequentially anodized in the same anodization electrolyte. The chemical composition of the electrolyte was measured after each anodization and correlated with the anodization current density, temperature, electrical conductivity, and pH of the electrolyte and with the morphology, structure, composition, and photocatalytic activity of the resulting TiO(2) nanotube films. It was found that the length of the TiO(2) nanotubes decreased with the age of the electrolyte due to its lower conductivity. The subsurface chemical composition was evaluated by time of flight secondary ion mass spectrometry (ToF SIMS) analyses, and the integrated ToF SIMS signals over a depth of 250 nm for the TiO(2) nanotube films showed that the concentration of F(–) in the annealed TiO(2) film increased with each subsequent anodization due to the increased pH value of the electrolyte. As a consequence, the concentration of the OH(–) and O(2)(–) species decreased, which is a major reason for the reduced photocatalytic activity of the TiO(2) films. It is proposed that the length of the TiO(2) nanotubes does not play a decisive role in determining the photocatalytic activity of the TiO(2) nanotube films. Finally, the best measured degradation results of 60% for caffeine were thus achieved for the first anodized titanium discs. After that the efficiency gradually decreased for each subsequent anodized disc.
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spelling pubmed-77373292020-12-16 Influence of Anodization-Electrolyte Aging on the Photocatalytic Activity of TiO(2) Nanotube Arrays Suhadolnik, Luka Marinko, Živa Ponikvar-Svet, Maja Tavčar, Gašper Kovač, Janez Čeh, Miran J Phys Chem C Nanomater Interfaces [Image: see text] TiO(2) nanotubular films prepared using the anodic oxidation process applied to various forms of metal titanium are promising materials for photocatalytic applications. However, during successive anodizations in batch-anodization cells, the chemical composition of the NH(4)F- and water-based ethylene glycol electrolyte changes with each subsequent anodization, which greatly affects the final photocatalytic properties of the annealed TiO(2) nanotubular films. In the present study, 20 titanium discs (Φ 90 mm) were sequentially anodized in the same anodization electrolyte. The chemical composition of the electrolyte was measured after each anodization and correlated with the anodization current density, temperature, electrical conductivity, and pH of the electrolyte and with the morphology, structure, composition, and photocatalytic activity of the resulting TiO(2) nanotube films. It was found that the length of the TiO(2) nanotubes decreased with the age of the electrolyte due to its lower conductivity. The subsurface chemical composition was evaluated by time of flight secondary ion mass spectrometry (ToF SIMS) analyses, and the integrated ToF SIMS signals over a depth of 250 nm for the TiO(2) nanotube films showed that the concentration of F(–) in the annealed TiO(2) film increased with each subsequent anodization due to the increased pH value of the electrolyte. As a consequence, the concentration of the OH(–) and O(2)(–) species decreased, which is a major reason for the reduced photocatalytic activity of the TiO(2) films. It is proposed that the length of the TiO(2) nanotubes does not play a decisive role in determining the photocatalytic activity of the TiO(2) nanotube films. Finally, the best measured degradation results of 60% for caffeine were thus achieved for the first anodized titanium discs. After that the efficiency gradually decreased for each subsequent anodized disc. American Chemical Society 2020-01-21 2020-02-20 /pmc/articles/PMC7737329/ /pubmed/33343787 http://dx.doi.org/10.1021/acs.jpcc.9b09522 Text en This is an open access article published under a Creative Commons Attribution (CC-BY) License (http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html) , which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited.
spellingShingle Suhadolnik, Luka
Marinko, Živa
Ponikvar-Svet, Maja
Tavčar, Gašper
Kovač, Janez
Čeh, Miran
Influence of Anodization-Electrolyte Aging on the Photocatalytic Activity of TiO(2) Nanotube Arrays
title Influence of Anodization-Electrolyte Aging on the Photocatalytic Activity of TiO(2) Nanotube Arrays
title_full Influence of Anodization-Electrolyte Aging on the Photocatalytic Activity of TiO(2) Nanotube Arrays
title_fullStr Influence of Anodization-Electrolyte Aging on the Photocatalytic Activity of TiO(2) Nanotube Arrays
title_full_unstemmed Influence of Anodization-Electrolyte Aging on the Photocatalytic Activity of TiO(2) Nanotube Arrays
title_short Influence of Anodization-Electrolyte Aging on the Photocatalytic Activity of TiO(2) Nanotube Arrays
title_sort influence of anodization-electrolyte aging on the photocatalytic activity of tio(2) nanotube arrays
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7737329/
https://www.ncbi.nlm.nih.gov/pubmed/33343787
http://dx.doi.org/10.1021/acs.jpcc.9b09522
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