Kinetics of photocatalytic degradation of trichloroethylene in aqueous colloidal solutions of TiO2 and WO3 nanoparticles
Kinetics of photocatalytic degradation of trichloroethylene in aqueous colloidal solutions of TiO2 and WO3 nanoparticles
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DOI：
10.1016/j.jphotochem.2012.09.001
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发表时间：
2012-12-01
影响因子：
4.3
通讯作者：
Yamazaki, Suzuko
中科院分区：
文献类型：
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作者：
Seyama, Tomoaki;Adachi, Kenta;Yamazaki, Suzuko
研究了三氯乙烯(TCE)在锐钛矿型纳米二氧化钛(TiO2光催化剂)和纳米WO3光溶胶(WO3光溶胶)中的光催化降解动力学。二氧化钛胶体的光催化活性比WO_3高2.1倍。动力学分析给出了包含伽马值的相似的速率定律，伽马值表示光生电子与O-2反应的速率与光生电子的总消失率之比。反应温度对TiO2光催化性能没有影响，但反应温度越高，TCE在WO3溶胶中的氧化速率越快。温度效应的这种差异可以用伽马值来解释。WO_3和TiO_2溶胶的混合对ICE的光催化降解有促进作用，当WO_3：TiO_2摩尔比为1：2时，其光催化降解性能最佳。在混合溶胶中，得到了与WO_3溶胶相似的温度依赖性。提出了反应机理和速率定律来解释所获得的动力学数据。(C)2012爱思唯尔B.V.保留所有权利。
Kinetic studies on the photocatalytic degradation of trichloroethylene (TCE) were performed in TiO2 or WO3 aqueous sol which consisted of anatase nanocrystalline TiO2 of ca. 3.9 nm or WO3 spherical particles of ca. 17.6 nm. Photocatalytic activity of TiO2 colloid is higher than that of WO3 by a factor of 2.1. Kinetic analyses for both sols give a similar rate law containing gamma value which represents a ratio of the reaction rate of the photogenerated electrons with O-2 against the total disappearance rate of the photogenerated electrons. Reaction temperature did not affect the TiO2 photocatalysis whereas higher temperature increased the oxidation rate of TCE in the WO3 sol. Such a difference in the temperature effect was explained in terms of the gamma values. The photocatalytic degradation of ICE was enhanced by mixing the WO3 and the TiO2 sol and the best performance was obtained by using the mixed sol with WO3:TiO2 molar ratio of 1:2. In the mixed sol, the similar temperature dependence as in the WO3 sol was obtained. Reaction mechanism and the rate law are proposed to account for the obtained kinetic data. (C) 2012 Elsevier B.V. All rights reserved.