掺锡TiO2复合薄膜的制备和光催化性能的研究

通过溶胶-凝胶工艺在玻璃表面制备了均匀透明的掺锡锐钛矿型TiO₂光催化复合薄膜,用SEM、XRD、XPS等对薄膜进行了表征。薄膜中除含有Ti,O, Sn等元素外,还存在一定量的来自有机前驱物未完全燃烧的C元素和从玻璃表面扩散到薄膜中的Na和Ca元素。甲基橙水溶液的光催化降解实验表明:掺锡TiO₂复合薄膜的表观降解速率常数明显高于未掺锡TiO₂薄膜的表观降解速率常数,这为进一步提高TiO₂薄膜的光催化活性开辟了新的途径。 

PREPARATION OF Sn-DOPED TiO2 COMPOSITE THIN FILMS BY SOL-GEL PROCESSING AND THEIR PHOTO-CATALYTIC PROPERTIES

The uniform, transparent anatase Sn-doped TiO2 composite thin films deposited on glass substrates were prepared by sol-gel processing. Sn-doped TiO2 films were composed of TiO2 sphere particles in size of 50～100 nm. The thickness of TiO2 films prepared by 1 cycle (from dipping to teat-treatment at 500℃,1 h) is 0.09 μm or so. Anatase TiO2 films show some orientation effect in (101) peak. XPS results have showed that besides Ti, O and Sn elements in films there are a certain amount of residual carbon from the starting organometallic components and a small amount of Na and Ca elements diffused from the glass substrates. Photo-catalytic degradation of Methyl orange aqueous solution has indicated that the sol-gel derived Sn-doped TiO2 films show good photo-catalytic activity, and its apparent degradation rate constant k is larger than that of un-doped TiO2 films. These results are explained on the basis of the principle of charge separation in an SnO2/TiO2 composite semiconductor system．