Highly selective deethylation of rhodamine B: Adsorption and photooxidation pathways of the dye on the TiO2/SiO2 composite photocatalyst

The photocatalytic degradation of Rhodamine B (RhB) with TiO2 and TiO2/SiO2 in the aqueous dispersion was investigated under both the visible light (λ> 480 nm) and UV irradiation. The detailed photocatalytic oxidative process of RhB under these different conditions was revealed by measurement of...

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Main Authors: Feng Chen, Jincai Zhao, Hisao Hidaka
Format: Article
Language:English
Published: Wiley 2003-01-01
Series:International Journal of Photoenergy
Online Access:http://dx.doi.org/10.1155/S1110662X03000345
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author Feng Chen
Jincai Zhao
Hisao Hidaka
author_facet Feng Chen
Jincai Zhao
Hisao Hidaka
author_sort Feng Chen
collection DOAJ
description The photocatalytic degradation of Rhodamine B (RhB) with TiO2 and TiO2/SiO2 in the aqueous dispersion was investigated under both the visible light (λ> 480 nm) and UV irradiation. The detailed photocatalytic oxidative process of RhB under these different conditions was revealed by measurement of the isoelectric points of the catalysts, UV-VIS spectra, HPLC and LC-MS. RhB adsorbs on the surface of TiO2/SiO2 particles by the positively-charged diethylamino group while, in the case of net TiO2, it adsorbs through the negatively-charged carboxyl group under the experimental conditions (pH ∼ 4.3). In the RhB-TiO2/SiO2 system, RhB firstly underwent a highly selective stepwise deethylation process before the destruction of the chromophore structure under visible light irradiation. The average yield of the every deethylation step was higher than 86%. It is confirmed that visible light-induced photocatalytic degradation of dye proceeds on the surface of catalysts rather than in the bulk solution and active oxygen species preferentially attack the molecular portion that connects directly to the surface of catalysts. This work provides a possibility for the modification of the surface characteristics of TiO2 to adsorb effectively the special colored organic molecules in selective mode for selective modification or deeply extent photooxidation.
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spelling doaj-art-e90b964c317a44459caf5c3b415330082025-02-03T05:51:26ZengWileyInternational Journal of Photoenergy1110-662X2003-01-015420921710.1155/S1110662X03000345Highly selective deethylation of rhodamine B: Adsorption and photooxidation pathways of the dye on the TiO2/SiO2 composite photocatalystFeng Chen0Jincai Zhao1Hisao Hidaka2Frontier Research Center for the Global Environment Protection, Meisei University, 2-1-1 Hodukubo, Hino, Tokyo 191-8506, JapanThe Laboratory of Photochemistry, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, ChinaFrontier Research Center for the Global Environment Protection, Meisei University, 2-1-1 Hodukubo, Hino, Tokyo 191-8506, JapanThe photocatalytic degradation of Rhodamine B (RhB) with TiO2 and TiO2/SiO2 in the aqueous dispersion was investigated under both the visible light (λ> 480 nm) and UV irradiation. The detailed photocatalytic oxidative process of RhB under these different conditions was revealed by measurement of the isoelectric points of the catalysts, UV-VIS spectra, HPLC and LC-MS. RhB adsorbs on the surface of TiO2/SiO2 particles by the positively-charged diethylamino group while, in the case of net TiO2, it adsorbs through the negatively-charged carboxyl group under the experimental conditions (pH ∼ 4.3). In the RhB-TiO2/SiO2 system, RhB firstly underwent a highly selective stepwise deethylation process before the destruction of the chromophore structure under visible light irradiation. The average yield of the every deethylation step was higher than 86%. It is confirmed that visible light-induced photocatalytic degradation of dye proceeds on the surface of catalysts rather than in the bulk solution and active oxygen species preferentially attack the molecular portion that connects directly to the surface of catalysts. This work provides a possibility for the modification of the surface characteristics of TiO2 to adsorb effectively the special colored organic molecules in selective mode for selective modification or deeply extent photooxidation.http://dx.doi.org/10.1155/S1110662X03000345
spellingShingle Feng Chen
Jincai Zhao
Hisao Hidaka
Highly selective deethylation of rhodamine B: Adsorption and photooxidation pathways of the dye on the TiO2/SiO2 composite photocatalyst
International Journal of Photoenergy
title Highly selective deethylation of rhodamine B: Adsorption and photooxidation pathways of the dye on the TiO2/SiO2 composite photocatalyst
title_full Highly selective deethylation of rhodamine B: Adsorption and photooxidation pathways of the dye on the TiO2/SiO2 composite photocatalyst
title_fullStr Highly selective deethylation of rhodamine B: Adsorption and photooxidation pathways of the dye on the TiO2/SiO2 composite photocatalyst
title_full_unstemmed Highly selective deethylation of rhodamine B: Adsorption and photooxidation pathways of the dye on the TiO2/SiO2 composite photocatalyst
title_short Highly selective deethylation of rhodamine B: Adsorption and photooxidation pathways of the dye on the TiO2/SiO2 composite photocatalyst
title_sort highly selective deethylation of rhodamine b adsorption and photooxidation pathways of the dye on the tio2 sio2 composite photocatalyst
url http://dx.doi.org/10.1155/S1110662X03000345
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AT jincaizhao highlyselectivedeethylationofrhodaminebadsorptionandphotooxidationpathwaysofthedyeonthetio2sio2compositephotocatalyst
AT hisaohidaka highlyselectivedeethylationofrhodaminebadsorptionandphotooxidationpathwaysofthedyeonthetio2sio2compositephotocatalyst