【摘要】 采用溶胶 凝胶法制备了nano TiO2 SnO2 复合溶胶 ,经一次镀膜就能在玻璃上得到没有缺陷、结构紧密均匀的nano TiO2 SnO2 复合膜 .通过扫描电镜观察到复合膜颗粒为球形 ,比纯TiO2 膜的颗粒小 ,平均粒径为 15nm ,且粒径分布非常均匀 .以空气中的有机挥发物甲苯模拟污染物 ,测定了nano TiO2 SnO2 复合膜的光催化降解性能 .结果表明 ,n(SnO2 ) / n(TiO2 )=0 0 5的nano TiO2 SnO2 复合膜催化剂具有最高的光催化活性 ,且比纯TiO2 膜的活性高 ;甲苯初始浓度为 92 0mg/m3 时 ,反应 5h甲苯完全降解 .XRD分析表明 ,此复合物具有锐钛矿和金红石两种TiO2 晶相 ,没有检测到SnO2 的特征峰 .更多还原

【Abstract】 In recent years heterogeneous photocatalytic oxidation has received considerable attention as an alternative remedial technology since the method offers a lot of advantages over conventional technologies. Titanium dioxide is an inexpensive, safe and very stable catalyst with high photocatalytic efficiency for environment purification. Numerous photocatalytic reactions show that organic contaminants in water can be completely mineralized by irradiating them in the presence of TiO 2. In this paper, the photocatalytic oxidation of volatile organic compounds in gas phase has been studied by using nano TiO 2 SnO 2 composite film as the catalyst. Nano TiO 2 SnO 2 composite gel prepared by the sol gel method was deposited on a glass substrate by dip coating only one time and uniform transparent nano TiO 2 SnO 2 composite films were obtained after calcination at 450 ℃. The film was characterized by scanning electron microscopy, and the results show that the uniform composite film has a narrow particle size distribution with an average particle diameter of 15 nm, which is smaller than that of thepure SnO 2 film (20 nm). The composite film has been employed in photocatalytic degradation of waste gas with toluene, and the results show that the photocatalytic activity of the composite films is higher than that of pure TiO 2 film. Under the initial toluene concentration of 920 mg/m 3 and reaction time of 5 h, the photocatalytic degradation of toluene over the catalyst of n (SnO 2)/ n (TiO 2)=0 05 is approximately 100%. The crystal structure of the nano TiO 2 SnO 2 composite catalyst has been examined by XRD. The results indicate that TiO 2 is composed of anatase and rutile phase, and the crystal structure of tin dioxide has not been detected.更多还原