Plasmon-induced reduction of bromate with Au-Ag-AgI/Al sub(2)O sub(3) under visible-light irradiation

BACKGROUND The plasmon-induced photocatalytic reduction of bromate (BrO sub(3) super(-)) was investigated in visible-light irradiated Au-Ag-AgI/Al sub(2)O sub(3) suspension. The BrO sub(3) super(-) reduction process was studied in detail. RESULTS The catalyst was found to be highly effective for the...

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Bibliographic Details
Published in:Journal of chemical technology and biotechnology (1986) 2014-09, Vol.89 (9), p.1425-1431
Main Authors: Peng, Tianwei, Tu, Jinjun, Hu, Chun, Hu, Xuexiang, Zhou, Xuefeng
Format: Article
Language:English
Subjects:
Aluminum oxide
Catalysts
Ethyl alcohol
Excitation
Gold
Irradiation
Photocatalysis
Reduction
Surface chemistry
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Summary:BACKGROUND The plasmon-induced photocatalytic reduction of bromate (BrO sub(3) super(-)) was investigated in visible-light irradiated Au-Ag-AgI/Al sub(2)O sub(3) suspension. The BrO sub(3) super(-) reduction process was studied in detail. RESULTS The catalyst was found to be highly effective for the reduction of BrO sub(3) super(-) from pH 3 to 6. An enhancement of the electrical interaction between BrO sub(3) super(-) and the positively charged surface of the photocatalyst favored adsorption and reduction of BrO sub(3) super(-). Organic compounds such as ethanol could react as sacrificial electron donors with excited holes (h super(+)) on the metal nanoparticles (NPs) to accelerate electron transfer, inhibiting the release of metal ions and the recombination of h super(+) and electrons, hence promoting photocatalytic reduction of BrO sub(3) super(-). Electron quenching and cyclic voltammetry studies under a variety of experimental conditions verified that BrO sub(3) super(-) trapped conduction band electrons of AgI from the excited metal NPs were reduced, competing with O sub(2). CONCLUSION The photocatalyst Au-Ag-AgI/Al sub(2)O sub(3) exhibited particularly good reduction of BrO sub(3) super(-) under visible-light irradiation. The BrO sub(3) super(-) reduction was highly favored at acidic condition due to the greater adsorption of BrO sub(3) super(-) onto the catalyst. This finding indicates that this visible-light-driven catalyst could be applied to the reduction of some oxidative pollutants or even simultaneous removal of both oxidative and reductive pollutants. copyright 2013 Society of Chemical Industry
ISSN:0268-2575
1097-4660
DOI:10.1002/jctb.4227