天然沸石对提高TiO_2光催化活性的作用  

Effect of Natural Zeolite Supports for Photoactive TiO_2 During the Photodegradation Process

作　　者：牟柏林[1] 李芳菲[2] 侯天意[2] 孙申美[2] 王瑛玮[2] 祖胜男[2] 

机构地区：[1]北华大学分析测试中心,吉林吉林市132013 [2]吉林大学材料科学与工程学院,长春130026

出　　处：《吉林大学学报（地球科学版）》2006年第4期668-672,共5页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金项目(40172020);吉林省科技厅基金项目(2004-0329)

摘　　要：以天然沸石为载体,研究了其负载TiO2后对甲基橙溶液的光催化降解效果,探讨了TiO2与沸石的结合类型。通过对负载前后反应动力学模式变化的研究,阐释TiO2/沸石体系的光催化反应进程。从复合前后样品的AFMI、R、发射光谱变化上看,部分TiO2与沸石载体形成了新的Ti-O-Si或Ti-O-Al的化学键。光催化实验结果和动力学分析显示,在反应的初始阶段,当TiO2中引入多孔的沸石载体后,催化剂对甲基橙的降解过程由原来纯粹的吸附控制模式向反应控制模式转变,但还没有达到纯粹的反应控制的程度。沸石载体是通过提高吸附过程的速率,来提升初始阶段的光催化反应速率(R0)的。The porous natural zeolites have been employed as the TiO2 supports, and the photocatalytic process of TiO2/zeolite on methyl orange （MO） has been studied. The interface mechanism between the TiO2 and the natural zeolite has been discussed, and the change of the kinetic process before and after TiO2 loading has been studied for the first time. The “super reaction area” model has been brought out for liquid system, in order to explain the photocatalytic process of the TiO2/zeolite system. The AFM, IR and spectra analysis, a certain amount of TiO2 combined with natural zeolite by Ti-O-Si or Ti-O-AI chemical bond. At the initial stage of photcatalytic degradation （PCD） of MO, the addition of nature zeolite supports have made the initial reaction change from original poor “adsorption controlled” process to the “reaction controlled” process. Since all of the reaction rates of TiO2/zeolite are higher than the pure TiO2 powder, it＇s obvious that the zeolite supports have enhanced the rate of the slower adsorption process resulting in the increase of the initial reaction rate R0. The first-order reaction rate k, shows that no matter what kind of process controlled the PCD process at the initial stage the whole process of PCD must be an adsorption controlling process undoubtedly because of the proliferating of the medial product.

关 键 词：天然沸石 TI02 光催化作用 机理 

分 类 号：O644[理学—物理化学]