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

270Citations
Citations of this article
192Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

The photocatalytic degradation of Rhodamine B (RhB) with TiO 2 and TiO 2/SiO 2 in the aqueous dispersion was investigated under both the visible light (λ > 480nm) 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 TiO 2/SiO 2 particles by the positively-charged diethylamino group while, in the case of net TiO 2, it adsorbs through the negatively-charged carboxyl group under the experimental conditions (pH ∼ 4.3). In the RhB-TiO 2/SiO 2 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 TiO 2 to adsorb effectively the special colored organic molecules in selective mode for selective modification or deeply extent photooxidation.

Cite

CITATION STYLE

APA

Chen, F., Zhao, J., & Hidaka, H. (2003). Highly selective deethylation of Rhodamine B: Adsorption and photooxidation pathways of the dye on the TiO2/SiO2 composite photocatalyst. International Journal of Photoenergy, 5(4), 209–217. https://doi.org/10.1155/S1110662X03000345

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free