纳米TiO_2-SiO_2自清洁复合薄膜制备及其光催化机理

Studies on the Preparation and Photocatalytic Mechanism of Self-cleaning TiO_2-SiO_2 Nanometer Composite Thin Films

采用溶胶-凝胶法在普通载玻片上制备TiO2-SiO2复合薄膜,研究SiO2添加量对光催化活性的影响,探讨TiO2光催化的机理.结果表明:光催化性随SiO2含量的增加而增加,但SiO2添加量过大,煅烧过程中对TiO2锐钛矿相晶粒生长有抑制作用,而且光催化活性有所下降.当SiO2添加量为30%时,在紫外光照1h时TiO2-SiO2薄膜的光催化活性最佳.

TiO2 - SiO2 thin films were prepared on slide glass substrates by sol - gel method. The effects of the SiO2 amount on photocatalytic activity of TiO2 - SiO2thin films were investigated and photocatalytic mechanism of TiO2 was explored. The results indicated that photocatalytic activity increases and the photocatalytic activity of TiO2 decreases slightly with the increase of SiO2 content. However, the extra addition of SiO2 has a suppressive effect on the crystal growth of anatase in calcinations. After UV - irradiating 1 h, the photocatalytic activity of TiO2 - SiO2 thin films reached to the highest spot when the amount of SiO2 is 30% （in mole）.