Co掺杂改性纳米TiO_2颗粒的制备及其光催化性能

Preparation and Photocatalytic Activity of Co-doped TiO_2 Nano-particles

以钛酸丁酯为前驱体,冰醋酸为螯合剂,利用溶胶-凝胶(Sol-Gel)法制备出掺杂金属Co复合改性的纳米TiO2光催化剂.采用X射线衍射(XRD)、透射电子显微镜(TEM)、N2吸附/解吸BET技术对其组织结构进行表征,并研究了不同掺杂量对TiO2相变和光催化性能的影响,确定了最佳的Co掺杂量和热处理温度.结果表明,Co2+掺杂对锐钛矿型TiO2有稳定作用,阻碍TiO2由锐钛矿型向金红石型的转变.经过改性的纳米TiO2晶粒尺寸在10～20nm之间,Co-TiO2光催化剂的最佳热处理温度是500℃,最佳Co掺杂浓度为Co/TiO2(mol)=0.1,紫外光下照射3h,最高光催化降解甲基橙效率达到85%.

Co-doped nanometer TiO2 photocatalyst was prepared by sol-gel method with Ti（OBu）4 as precursor and HAC as complexation reagent. The composition and microstructure of prepared Co-TiO2 nanoparticles were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM） and N2 adsorption-desorption isotherm. The structure of the nanocomposite and the relationship between the concentration of Co and its photocatalytic activity were also studied. The optimum molar ratio of Co/Ti and heat treatment temperature were obtained. The results showed that with doping of Co, anatase-TiO2 became more stable and the phase transformation from anatase to rutile was blocked. The particle sizes of Co-TiO2 were in the range of 10-20 nm. The optimal heat treatment temperature of Co-TiO2 powder was 500℃ and molar ratio of Co/Ti 0.1. Under these conditions photocatalytic decomposition rate of methyl orange solution reached the highest, up to 85% under 3 h irradiation with ultraviolet light