钛金属有机物热解制备TiO2-SiO2复合膜及其光催化活性研究

混有一定量SiO_2溶胶的钛金属有机化合物膜液通过旋液成膜法制备前驱物膜 ，经热解得到TiO_2-SiO_2复合膜。于610 ℃焙烧15min所得复合膜(Ti:Si=9:1)经 SEM，XRD，UV-vis和XPS研究表明，膜面由30 nm * 200 nm大小的晶体粒子组成， 结构致密，膜厚约200 nm，其可见光透过率为玻璃基质的80%，膜表面Ti~(3+)OH~- 的比值为1.06。对不同SiO_2含量的膜液凝胶进行DSC分析显示，少量的SiO_2就能 显著提高TiO_2锐钛矿型晶相的形成温度。膜的光催化活性研究表明一定量的Fe~ (3+)有利于提高膜的光催化活性，但是如果以氯化物的形式加入则对光催化反应不 利，铬的氯化物同样如此。另外，在钛金属有机物热解制备TiO_2-SiO_2复合膜中 ，溶胶SiO_2不利于光催化反应，但是它可以改善膜的耐磨性。

Preparation and Photo-catalytic Activity of TiO_2-SiO_2 Thin Films by Pyrolysis of Organo-Titanium Compounds

TiO_2-SiO_2 composite thin films can be obtained by calcinating the precursor films prepared with spin-coating that comprise organo- titanium compounds and SiO_2 sol. The film sample (Ti: Si = 9: 1) obtained through calcinating at 610 °C for 15 min was studied with SEM, XRD, UV-vis and XPS. The research results show that the film is made up with about 30 nm x 200 nm crystalline particles densely with its thickness of about 200 nm, transmittance rate of visible light is 80% of that of glass substrate and the Ti~(3+)/OH~- ratio on surface of the composite thin film is 1.06. The formation temperature of anatase phase could be elevated mai'kedly by mixing a small quantity of SiO2, which was confirmed by DSC analysis of the gel of film solutions containing different amounts of SiO_2. The studies on photo- catalytic activities of the films revealed that doping certain amount of Fe~(3+) (not in chloride form) is in favor of photo-catalytic reaction. The same holds true in doping Cr~(3+) . In addition, mixing SiO2 can improve the abradability of films, although it adversely affects the photo-catalytic activities.