Photocatalytic activity and kinetics for acid yellow degradation over surface composites of TiO_2-coated activated carbon under different photocatalytic conditions  

外负载TiO_2/活性炭在不同条件下降解酸性黄的光催化性能及其动力学(英文)

作　　者：曾孟雄[1] 李佑稷[1] 马明远[1] 陈伟[1] 李雷勇[1] 

机构地区：[1]吉首大学化学化工学院,吉首416000

出　　处：《Transactions of Nonferrous Metals Society of China》2013年第4期1019-1027,共9页中国有色金属学报（英文版）

基　　金：Project(50802034) supported by the National Natural Science Foundation of China;Project(11A093) supported by the Key Project Foundation by the Education Department of Hunan Province,China

摘　　要：TiO2-coated activated carbon surface （TAs） composites were prepared by a sol-gel method with supercritical pretreatment. The photocatalytic degradation of acid yellow （AY） was investigated under UV radiation to estimate activity of catalysts and determine the kinetics. And the effects of parameters including the initial concentration of AY, light intensity and TiO2 content in catalysts were examined. The results indicate that TAs has a higher efficiency in decomposition of AY than P25, pure TiO2 particles as well as the mixture of TiO2 powder and active carbon. The photocatalytic degradation rate is found to follow the pseudo-first order kinetics with respect to the AY concentration. The new kinetic model fairly resembles the classic Langmuir-Hinshelwood equation, and the rate constant is proportional to the square root of the light intensity in a wide range. However, its absorption performance depends on the surface areas of catalysts. The model fits quite well with the experimental data and elucidates phenomena about the effects of the TiO2 content in TAs on the degradation rate.以超临界流体沉积法处理过的活性炭(AC)为载体,采用溶胶-凝胶法制备外负载TiO_2/AC(TAs)光催化材料。在紫外光照射下,通过对可溶性染料酸性黄(AY)的降解反应,考察外负载TiO_2/AC复合体的光催化性能并建立光催化降解动力学,同时探讨酸性黄初始溶液浓度、光强度、催化剂浓度对其光催化降解性能的影响。结果表明,TAs具有很高的光催化活性,对酸性黄的光催化性能比TiO_2+AC、TiO_2和P25的高。外负载TiO_2/AC对不同初始浓度酸性黄的光催化降解符合一级动力学,这种新的动力学模型符合经典的Langmuir-Hinshelwood定律且在较大范围内其降解速率常数与光强度的平方根成正比。然而,其吸附性能取决于光催化剂的比表面积。模型与实验数据较吻合,表明此模型能阐明催化剂TAs中TiO_2浓度对光催化性能的影响。

关 键 词：PHOTOCATALYSIS TiO2-coated activated carbon acid yellow composite catalyst 

分 类 号：X703[环境科学与工程—环境工程] O643.32[理学—物理化学]