Co掺杂对TiO2光催化剂结构与性能的影响

采用溶胶-凝胶法制备了Co掺杂的TiO2粉末, 利用透射电子显微镜、X射线光电子能谱、紫外可见光谱和X射线衍射技术对粉末进行了表征, 并利用环形光催化反应器对其光催化活性进行了测试. 结果表明, 随焙烧温度的增加, Co/TiO2粉末的晶粒尺寸逐渐增大, 升至873 K时, 钴元素以CoTiO3形式从TiO2中析出, 同时TiO2由锐钛矿型向金红石型发生转变, 相转变过程中晶格常数a和c以及晶胞体积发生收缩. 掺杂钴以后, 粉末的光谱吸收范围被拓展至可见光, 但是其光催化活性却明显降低.

Effects of Doping Cobalt on the Structures and Performances of TiO2 Photocatalyst

The Co-doped TiO2 powders were prepared by the sol-gel method, and characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis absorption spectroscopy, and X-ray diffraction. The photocatalytic activities of the powders were also measured by using an annulus photochemical reactor. The results showed that the grain size grew gradually with calcination temperatures. When the calcination temperature grew up to 873 K, the cobalt element separated out from TiO2 as CoTiO3. At the same time, TiO2 transferred from anatase to rutile phase. In phase transfer, crystal lattice constant a, c and cell volumes of TiO2 decreased. After doping with cobalt, the photon excited wavelength of the TiO2 powder was broadened to visible light, but the photocatalytic activity of the TiO2 powder decreased obviously.