低温下溶胶凝胶法制备TiO2纳米晶

从含过量水的溶胶出发，在室温下得到了TiO₂纳米晶。通过红外光谱，透射电子显微镜法和X射线粉末衍射法对含有过量水的溶胶体系中TiO₂纳米晶的室温形成机理进行了研究。与传统的溶胶凝胶法相比，在改良的溶胶凝胶体系中，在缩聚反应之前由于水过量使得钛的先驱体快速且充分的水解，从而生成TiO₆]基团，随之形成TiO₂纳米晶。晶粒的尺寸为约3.5 nm，该法得到的TiO₂纳米晶比传统溶胶凝胶法得到的TiO₂纳米晶和商用光催化剂德固赛P25具有更好的光催化活性。

Preparation of Nanocrystalline TiO2 by Sol-Gel-Method at Room Temperature

Nanoerystalline titania (TiO2) particles were obtained at room temperature by a modified sol-gel method starting from a solution with large amount of water.The nanoerystalline TiO2 particles prepared with large amount of water at room temperature were characterized by IR,TEM and XRD.Comparing with conventional sol-gel method,the present system offers quick and complete hydrolysis of titanium precursor before polycondensation,thus resulting in TiO6] units,and the formation of nanocrystalline TiO2 particles with an average grain size of 3.5 nm.Moreover,the as-prepared nanocrystalline TiO2 powders exhibit a better photocatalytic activity than both of the powders prepared by conventional sol-gel method and the commercial photocatalyst Degussa P25.