论文部分内容阅读
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3.5nm,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。
Starting from an excess of water-containing sol, TiO2 nanocrystals were obtained at room temperature. The formation mechanism of TiO2 nanocrystals in sol system containing excess water was studied by infrared spectroscopy, transmission electron microscopy and X-ray powder diffraction. Compared with the traditional sol-gel method, in the modified sol-gel system, the [TiO6] group is formed due to the excess of water before the polycondensation reaction so that the titanium precursor can be rapidly and fully hydrolyzed, followed by the formation of TiO2 nanocrystals . The size of the grains is about 3.5nm, the TiO2 nanocrystals obtained by the method have better photocatalytic activity than the TiO2 nanocrystals obtained by the traditional sol-gel method and the commercial photocatalyst Degussa P25.