Plasmonic Titania Photocatalysts Active under UV and Visible-Light Irradiation: Influence of Gold Amount, Size, and Shape

Plasmonic titania photocatalysts were prepared by titania modification with gold by photodeposition. It was found that for smaller amount of deposited gold (≤0.1 wt%), anatase presence and large surface area were beneficial for efficient hydrogen evolution during methanol dehydrogenation. After tes...

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Main Authors: Ewa Kowalska, Sven Rau, Bunsho Ohtani
Format: Article
Language:English
Published: Wiley 2012-01-01
Series:Journal of Nanotechnology
Online Access:http://dx.doi.org/10.1155/2012/361853
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author Ewa Kowalska
Sven Rau
Bunsho Ohtani
author_facet Ewa Kowalska
Sven Rau
Bunsho Ohtani
author_sort Ewa Kowalska
collection DOAJ
description Plasmonic titania photocatalysts were prepared by titania modification with gold by photodeposition. It was found that for smaller amount of deposited gold (≤0.1 wt%), anatase presence and large surface area were beneficial for efficient hydrogen evolution during methanol dehydrogenation. After testing twelve amounts of deposited gold on large rutile titania, the existence of three optima for 0.5, 2 and >6 wt% of gold was found during acetic acid degradation. Under visible light irradiation, in the case of small gold NPs deposited on fine anatase titania, the dependence of photoactivity on gold amount was parabolic, and large gold amount (2 wt%), observable as an intensively coloured powder, caused photoactivity decrease. While for large gold NPs deposited on large rutile titania, the dependence represented cascade increase, due to change of size and shape of deposited gold with its amount increase. It has been thought that spherical/hemispherical shape of gold NPs, in comparison with rod-like ones, is beneficial for higher level of photoactivity under visible light irradiation. For all tested systems and regardless of deposited amount of gold, each rutile Au/TiO2 photocatalyst of large gold and titania NPs exhibited much higher photoactivity than anatase Au/TiO2 of small gold and titania NPs.
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issn 1687-9503
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series Journal of Nanotechnology
spelling doaj-art-bb0966dfefa24059977ac72b348184062025-02-03T06:11:25ZengWileyJournal of Nanotechnology1687-95031687-95112012-01-01201210.1155/2012/361853361853Plasmonic Titania Photocatalysts Active under UV and Visible-Light Irradiation: Influence of Gold Amount, Size, and ShapeEwa Kowalska0Sven Rau1Bunsho Ohtani2Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, GermanyInstitute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, GermanyCatalysis Research Center, Hokkaido University, North 21, West 10, Sapporo 001-0021, JapanPlasmonic titania photocatalysts were prepared by titania modification with gold by photodeposition. It was found that for smaller amount of deposited gold (≤0.1 wt%), anatase presence and large surface area were beneficial for efficient hydrogen evolution during methanol dehydrogenation. After testing twelve amounts of deposited gold on large rutile titania, the existence of three optima for 0.5, 2 and >6 wt% of gold was found during acetic acid degradation. Under visible light irradiation, in the case of small gold NPs deposited on fine anatase titania, the dependence of photoactivity on gold amount was parabolic, and large gold amount (2 wt%), observable as an intensively coloured powder, caused photoactivity decrease. While for large gold NPs deposited on large rutile titania, the dependence represented cascade increase, due to change of size and shape of deposited gold with its amount increase. It has been thought that spherical/hemispherical shape of gold NPs, in comparison with rod-like ones, is beneficial for higher level of photoactivity under visible light irradiation. For all tested systems and regardless of deposited amount of gold, each rutile Au/TiO2 photocatalyst of large gold and titania NPs exhibited much higher photoactivity than anatase Au/TiO2 of small gold and titania NPs.http://dx.doi.org/10.1155/2012/361853
spellingShingle Ewa Kowalska
Sven Rau
Bunsho Ohtani
Plasmonic Titania Photocatalysts Active under UV and Visible-Light Irradiation: Influence of Gold Amount, Size, and Shape
Journal of Nanotechnology
title Plasmonic Titania Photocatalysts Active under UV and Visible-Light Irradiation: Influence of Gold Amount, Size, and Shape
title_full Plasmonic Titania Photocatalysts Active under UV and Visible-Light Irradiation: Influence of Gold Amount, Size, and Shape
title_fullStr Plasmonic Titania Photocatalysts Active under UV and Visible-Light Irradiation: Influence of Gold Amount, Size, and Shape
title_full_unstemmed Plasmonic Titania Photocatalysts Active under UV and Visible-Light Irradiation: Influence of Gold Amount, Size, and Shape
title_short Plasmonic Titania Photocatalysts Active under UV and Visible-Light Irradiation: Influence of Gold Amount, Size, and Shape
title_sort plasmonic titania photocatalysts active under uv and visible light irradiation influence of gold amount size and shape
url http://dx.doi.org/10.1155/2012/361853
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AT svenrau plasmonictitaniaphotocatalystsactiveunderuvandvisiblelightirradiationinfluenceofgoldamountsizeandshape
AT bunshoohtani plasmonictitaniaphotocatalystsactiveunderuvandvisiblelightirradiationinfluenceofgoldamountsizeandshape