溶胶-凝胶法制备掺铈纳米TiO2光催化剂降解NO2-的研究

利用X射线粉晶衍射、扫描电镜、透射电镜等方法分析煅烧温度、保温时间等因素对以溶胶-凝胶法制备的纳米TiO2及掺铈纳米TiO2光催化剂的相组成、晶粒大小的影响，煅烧温度升高使晶粒粒径增大并使物相组成发生改变，保温时间增加使晶粒粒径增大以及结晶度增高；利用所制备样品对亚硝酸盐进行光催化降解试验研究，结果表明样品的制备条件、光催化剂的晶粒大小、光催化时间对亚硝酸盐的降解率有重要影响，铈的掺入有利于提高亚硝酸盐的降解率，掺铈量在1％～3％范围内，亚硝酸盐的光催化降解率随掺铈量的增加而提高。

Ce4+-DOPED TiO2 NANO-CRYSTALLINE PREPARED BY A SOL-GEL METHOD AND ITS PHOTOCATALYTIC PERFORMANCE FOR NO2-

Nanocrystalline TiO_2 doped with Ce 4+ has been prepared by a sol-gel method,the synthesis was investigated by x-ray powder diffraction,SEM and TEM. The relationship between the influence factors such as calcination temperature, holding time and the synthesis phase compositions, crystalline size has been discussed. Particular suspensions of nanosized (particle size less than 20 nm) anatase mixed with rutile TiO_2 and Ce 4+-doped TiO_2 under UV irradiation in a glass photoreactor catalyzed the degradation of NO_2- ion. Both nanosized anatase mixed rutile TiO_2 and Ce 4+-doped TiO_2 have a high photocatalytic activity. However nanosized Ce 4+-doped TiO_2 has a much higher photocatalytic activity than anatase mixed rutile TiO_2. The results show that catalyst preparation conditions, crystalline size, photo catalysis time have an important influence on the TiO_2. With the increase of Ce 4+ ions concentration (1%Ce~3%Ce) in nanometer TiO_2, the photocatalytic activity of catalyst increases also.