多孔二氧化钛微球的制备、表征及其光催化性能

Preparation,Characterization and Photocatalytic Performance of Porous TiO_2 Micro-beads

以Lutensol TO（异构十三醇聚氧乙烯醚）系列非离子表面活性剂为辅助剂,采用溶胶-凝胶法制备了比表面积高、孔径分布窄的锐钛矿型TiO2多孔微球,并用透射电镜、扫描电镜、热重-差热分析、X射线衍射和氮吸附进行了表征.以亚甲基蓝降解为模型反应评价了其光催化性能,并与商品化TiO2Degussa P25进行了比较.实验结果表明,样品在425℃焙烧后,形成具有孔状结构的锐钛矿型TiO2微球,粒径为0.7-1.0μm,比表面积为70.5 m^2/g,总孔容为0.12 cm^3/g,平均孔径为4.26nm,晶粒尺寸为12 nm.这种多孔TiO2微球具有较高的催化活性,与Degussa P25纳米TiO2的催化活性相当.

Nanocrystal and porous TiO2 microbeads with high surface area and narrow pore size distribution were prepared by sol-gel technique in the presence of Lutensol TO series （iso-tridecanol） polyoxyethylene ether nonionic surfactants. The resultant TiO2 microbeads were characterized by TEM, SEM, TG-DSC, XRD, and N2 adsorption. The photocatalytic performance of TiO2 microbeads was evaluated through degradation of methylene blue and compared with the commercial Degussa P25 nano-TiO2. The results showed that at optimal treatment temperature of 425 ℃, anatase-type TiO2 microbeads with particle size of 0.7-1.0μm were obtained. The microbeads have porous structure with a BET specific surface area of 70.5 m^2/g, total pore volume of 0.12 cm^3/g, average pore diameter of 4.26 nm, and crystal size of 12 nm. The TiO2 microbeads exhibited similar photocatalytic activity to Degussa P25 for the degradation of methylene blue.