TiO2 -SiO2 复合半导体气凝胶是一种新型纳米光催化氧化剂。本文以正硅酸乙酯、钛酸丁酯为原料 ,用溶胶—凝胶法经超临界干燥制备出了TiO2 -SiO2 复合半导体气凝胶。研究了TiO2 :SiO2 不同配比对溶胶—凝胶过程的影响 ;用BET、XRD、SEM、TEM等测试方法对其结构进行了表征 ;以苯酚为探针考察了TiO2 -SiO2 复合半导体气凝胶的光催化氧化活性 ,并与普通锐钛矿型钛白粉光催化剂进行了对比。结果表明 :所制备的TiO2 -SiO2 复合半导体气凝胶具有大比表面积 ( 5 2 3.8m2 g-1) ,纳米多孔结构 (骨架颗粒约为 30 - 5 0纳米 ,孔洞尺寸为几十纳米 ) ;其光催化氧化活性大大高于普通锐钛矿型二氧化钛 TiO2-SiO2 composite semiconductor airgel is a new type of nano-photocatalyst. In this paper, a series of TiO2-SiO2 composite semiconductor aerogels were prepared by using orthosilicate and butyl titanate as raw materials. The effect of TiO2 / SiO2 ratio on the sol-gel process was investigated. The structure of the sol-gel process was characterized by BET, XRD, SEM and TEM. The photocatalytic activity of TiO2-SiO2 composite semiconductor aerogels Of photocatalytic oxidation activity, and compared with ordinary anatase titanium dioxide photocatalyst. The results show that the prepared TiO2-SiO2 composite semiconductor airgel has a large specific surface area (528m2 g-1), a nanoporous structure (skeleton particles of about 30-500 nm and pore size of several tens of nanometers); Its photocatalytic oxidation activity is much higher than ordinary anatase titanium dioxide