Chiing-Chang Chen, Chung‐Shin Lu, Y. Chung
Jul 5, 2006
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0
Influential Citations
43
Citations
Journal
Journal of Photochemistry and Photobiology A-chemistry
Abstract
Abstract The photodegradation of dye pollutants under visible light irradiation in TiO 2 dispersions continues to draw considerable attention because of the improving effective utilization of cost free solar energy and its potential application in treating wastewater from textile and photographic industries. To get a better understanding of the mechanistic details of this TiO 2 -assisted photodegradation of the ethyl violet dye (EV, N , N , N ′, N ′, N ″, N ″-hexaethylpararosaniline) with visible light irradiation, the intermediates of the process were identified and examined by the HPLC-ESI-MS technique in this research. The analytical results indicated that seventeen intermediates were separated and identified. The experimental results indicated that the N -de-ethylation degradation of EV dye took place in a stepwise manner to yield mono-, di-, tri-, tetra-, penta-, hexa- N -de-ethylated EV species and, most of all, to yield N- hydroxyethylated intermediates, which were found for the first time in TiO 2 -mediated photocatalysis process. The possible degradation pathways were proposed and discussed in this research. The reaction mechanisms of TiO 2 /Vis proposed in this research would be useful for future application in the decoloration of dyes.