H_4SiW_(12)O_(40)/TiO_2/空心微珠光催化降解联苯胺

采用复合型光催化剂H_4SiW_(12)O_(40)/TiO_2/空心微珠(cenospheres)光催化降解联苯胺,考察了联苯胺降解效果的影响因素,并运用FTIR和GS-MS技术分析了联苯胺光催化降解过程的主要中间产物,探讨了联苯胺可能的降解路径。实验结果表明:以125 W中压汞灯为光源,在溶液pH为6.3,初始联苯胺质量浓度为10 mg/L的条件下光反应240 min,联苯胺降解率达78%,比Ti_O2/空心微珠提高了24百分点;H_4SiW_(12)O_(40)/TiO_2/空心微珠光催化降解联苯胺符合表观一级动力学特征,且反应速率常数随初始联苯胺质量浓度的增加而减小;H_4SiW_(12)O_(40)/TiO_2/空心微珠具有较好的稳定性,易于分离,可重复利用;联苯胺光催化降解过程的主要中间产物为4-氨基联苯、4-氨基苯酚、对苯二酚和1,4-苯醌。

Photocatalytic degradation of benzidine on H4SiW12O40/TiO2/cenospheres

Benzidine was degraded using the composite photocatalyst H4SiW12O40/TiO2/cenospheres. The factors affecting the degradation efficiency were investigated. The intermediates in the process of benzidine photocatalytic degradation were characterized by FTIR and GC-MS technology,and the possible pathway of benzidine photocatalytic gradation was proposed. The experimental results show that:Under the conditions of using a 125 W medium pressure mercury lamp as light source,solution pH 6.3,initial benzidine mass concentration 10 mg/L and reaction time 240 min,the degradation rate of benzidine reaches 78%,which is higher than that of using TiO2/cenospheres photocatalyst by 24 percent;The photocatalytic degradation of benzidine on H4SiW12O40/TiO2/cenospheres fits the pseudo-first-order kinetics,and the reaction rate constant decreases with the increases of initial benzidine mass concentration;H4SiW12O40/TiO2/cenospheres shows good stability, and is easy to be separated and reused;The major intermediates in the process of benzidine photocatalytic degradation are identified as 4-aminobiphenyl,4-aminophenol,hydroquinone,and 1,4-benzoquinone.