文献类型：期刊文献

英文题名：Comparative studies of operational parameters of degradation of azo dyes in visible light by highly efficient WO_x/TiO₂ photocatalyst

作者：Sajjad, Ahmed Khan Leghari[1,2];Shamaila, Sajjad[1,2];Tian, Baozhu[1,2];Chen, Feng[1,2];Zhang, Jinlong[1,2,3]

机构：[1]E China Univ Sci & Technol, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[2]E China Univ Sci & Technol, Inst Fine Chem, Shanghai 200237, Peoples R China;[3]Guizhou Normal Univ, Sch Chem & Mat Sci, Guiyang 550001, Peoples R China

年份：2010

卷号：177

期号：1-3

起止页码：781

外文期刊名：JOURNAL OF HAZARDOUS MATERIALS

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000276154500101)】；

基金：This work has been supported by Science and Technology Commission of Shanghai Municipality (07JC14015), National Nature Science Foundation of China (20773039, 20977030), National Basic Research Program of China (973 Program, 2007CB613301, 2010CB732306) and the Ministry of Science and Technology of China (2006AA06Z379, 2006DFA52710). Sajjad Ahmed Khan Leghari and Shamaila Sajjad thank Higher Education Commission (Pakistan) for support.

语种：英文

外文关键词：WOx/TiO2; Photocatalysis; AO7; MO; Operational parameters

摘要：The multidimensional aspects of the photocatalytic activity were investigated in a systematic way by employing the dyes Acid Orange 7 (AO7) and Methyl Orange (MO) as substrates in terms of their degradation or conversion rates. 4.0% WOx/TiO2 nanocomposite demonstrated the best reactivity under visible light, allowing more efficient usage of solar light. The reduced form of W decreased the band gap and inhibited electron hole recombination efficiently. This composite was characterized by X-ray diffraction spectroscopy (XRD), UV-vis diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). A series of experiments were conducted to investigate the operational parameters under visible light irradiation such as optimization of nanocomposites wt%, change of pH, reuse of catalyst and initial dye concentration. The kinetics of the dyes degradation was found to follow the Langmuir-Hinshelwood model. Decomposition or mineralization was investigated with the changes of absorption spectra, pH, degradation efficiency and TOC removal in visible irradiation systems. FT-IR spectroscopy of these adsorbed dyes on WOx/TiO2 powder provided an insight to the mode of its adsorption on WOx/TiO2. It was found that the dye adsorbed on WOx/TiO2 underwent a series of oxidation steps which lead to decolorization and formation of a number of intermediates mainly aromatic and aliphatic acids. These intermediates were quantified by GC/GC-MS. (C) 2010 Elsevier B.V. All rights reserved.