Co掺杂改性纳米TiO2颗粒的制备及其光催化性能

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10~20 nm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3 h，最高光催化降解甲基橙效率达到85%.

Preparation and Photocatalytic Activity of Co-doped TiO2 Nano-particles

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.