二氧化钛介孔材料的制备

Synthesis and characterization of TiO_2 mesoporous materials

基于溶胶-凝胶过程,以十六烷基溴化铵为模板剂,合成了TiO2以及V/Ce/F-TiO2介孔材料。利用XRD、N2吸附、TEM、TG-DTA和UV-VisDRS等手段表征了材料的晶相组成、晶粒尺寸、介孔结构、热稳定性及吸光性能。通过系统研究表明,延长凝胶时间和优化陈化工艺可以得到TiO2介孔材料。TiO2和V/Ce/F/TiO2的平均孔径为3.1～5.1nm,最大比表面积可达189m2/g。焙烧温度大于450℃脱除模板剂时可引起孔道的塌陷,而掺杂V/Ce/F后可稳定材料的介孔结构。相对于纯TiO2光催化剂,掺杂V/F的TiO2吸光带边红移至可见光区。

Using cationic surfactant cetyltrimethylammonium bromide （CTAB） as the template, TiO2 and V/Ce/F-TiO2 mesoporous materials were synthesized by sol-gel method and characterized by X-ray powder diffractometry （XRD）, N2 absorptiometry, transmission electron microscope （TEM）, thermal analyses （TG-DTA） and UV-Vis DRS. By systematically studying the influence of the synthesis parameters such as gelling time, aging temperature and time, the optimal conditions for reproducible synthesis of mesoporous titania were established. Specific area up to 189 m^2.g^-1 was obtained with average pore size in the range of 3.1--5.1 nm. The mesoporous structure of pure TiO2 could be destroyed by removal of template at a calcination temperature of 450℃. However, the mesoporous structure of V/Ce/F-TiO2 which removed template by calcination was retaine, which suggests that the mesoporous structure can be stabilized by the doped ions. Shift of the adsorption edge to visible light was found for the doped mesoprous TiO2.