WO_3/TiO_2纳米材料的制备及光催化性能

Preparation,Characterization and Photo-catalytic Behavior of WO3/TiO_2 Nanopowder

采用溶胶-凝胶法制备 WO3/TiO2复合纳米光催化剂 .掺入 WO3、 TiO2锐钛矿 101峰的相对强度、平均晶粒直径与颗粒直径均减小，比表面积增大； WO3掺入摩尔比分别为 2％、 5％、 8％时，新的 LRS峰位分别出现在 797、 967及 969 cm－ 1;在 380－ 460 nm范围内， WO3/TiO2的反射率减小 .XPS分析表明， WO3/TiO2晶体中存在 W6＋、 W5＋、 W4＋和 Ti4＋、 Ti3＋ .以亚甲基蓝的光催化降解为反应模型，掺入 WO3后，光催化活性增强，掺入摩尔比为 2％时， WO3/TiO2的光催化活性最高 .还讨论了光催化活性与性质的关系 .

WO3/TiO2 samples were prepared by sol-gel process and characterized by means of XRD,LRS,TEM,DRS,BET,XPS. It has been shown that the mean crystal diameter and mean particle diameter of WO3/TiO2 samples decreased while the percent of anatase and specific surface area increased owing to the doping of WO3. New LRS peaks presented at 797,967 and 969 cm－ 1,respectively,when the concentration of doped WO3 was 2％ ,5％ and 8％ . The reflectance percentate of WO3/TiO2 samples was less than that of pure TiO2 in the range of 380-460nm. The XPS fitting analyses showed that there were W6＋、 W5＋、 W4＋ and Ti4＋、 Ti3＋ in the lattice of WO3/TiO2. Being a model reaction,the photo-catalytic degradation of methylene blue was investigated in TiO2 and WO3/TiO2 nanopowder suspension irradiated by high-pressure mercury lamp. As a result,the addition of WO3 to TiO2 greatly enhanced its photo-catalytic behavior,and the optimum concentration of WO3 in TiO2 was 2％ (molar percent). Moreover,the relationship between photo-activity and the physical and chemical properties of the samples have been discussed.