溶胶-凝胶法制备TiO2粉体及其光催化性能研究

以钛酸丁酯为前驱物,无水乙醇为溶剂,采用溶胶-凝胶法制备了TiO2粉体,并采用紫外分光光度计、XRD等表征手段对TiO2的粒度、晶型结构进行了表征,分析了煅烧温度、TiO2晶型比例、溶液初始pH值等因素对TiO2结构性能及光催化活性的影响.结果表明:TiO2的锐钛矿晶型与金红石晶型的转相温度为700 ℃左右;采用溶胶-凝胶法制备TiO2时,控制溶液的pH值为4,煅烧温度为600 ℃,所得产物晶型全部为锐钛矿;当无水乙醇与钛酸丁酯的体积比为10:1时,产物的粒径为617 nm;且当配制溶液pH值为4,煅烧温度为600℃条件下,煅烧时间为40~60 min时,所制备TiO2的光催化效果较好,降解率较高;当光催化体系的pH值为9、以质量浓度为10 mg/L的亚甲基兰溶液浸泡2 h,TiO2的用量为0.25 g/L时,产物的降解率高达95.3%.

The Synthesis of TiO2 Powder by Sol-Gel Method and the Study of Its Photocatalytic Activity

TiO2 powder was prepared by sol-gel method using butyl titanate as precursor in alcohol solution. The prepared powder was characterized by UV and XRD. The effects of calcination temperature, crystal ratio, the initial pH of preparation solution on structure and photocatalytic activity of TiO2 powder were analyzed. Results showed that anatase type TiO2 transferred into crystalline rutile TiO2 at approximately 700℃. The product crystal form was anatase when the pH of initial gel was 4, cinder temperature 600℃. The ratio of anatase type TiO2 to crystalline rutile TiO2 would affect the photocatalytic activities. When the volume ratio of absolute ethyl alcohol and butyl titanate was 10:1, the product grain size was 617 nm; the optimal catalytic effect and degradation rate was got with the preparation solution pH value being 4, calcination temperature 600℃ and time of 40~60 min. With the photocatalysis system pH being 9, soaked in methylene solution of 10 mg/L for 2 h, TiO2 being 0.25 g/L, the degradation rate reached 95.3%.