Comparison of photocatalytic activity of TiO2 film doped nonuniformly by Mn and Zn
(1. Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China;
2. Graduate School of Chinese Academy of Sciences, Beijing 100039, China;
3. Xin Tianlong Alcohol Co Ltd, Jilin 132000, China)
2. Graduate School of Chinese Academy of Sciences, Beijing 100039, China;
3. Xin Tianlong Alcohol Co Ltd, Jilin 132000, China)
Abstract: The thin films of TiO2, doped by Mn or Zn with nonuniform distribution, were prepared by sol-gel method under process control. The actinic absorption of the catalyst thin films was evaluated by UV-vis spectrophotometry. And the activity of the photocatalyst was evaluated by photocatalytic degradation kinetics of aqueous methyl orange under UV radiation. The results show that the photocatalytic activity of the TiO2 thin film can be evidently enhanced by Mn non-uniformly doping in the bottom layer and can be decreased by Mn doping in the surface layer. The activity of TiO2 thin film can be evidently enhanced by Zn non-uniform doping in either the bottom or the surface layer. But the activity of TiO2 is less affected by uniformly Zn doping. The different mechanisms for enhanced photocatalytic activity of Mn or Zn non-uniformly doped titanium dioxide film were discussed in terms of the separation of photon-generated carrier in the TiO2 films.
Key words: TiO2; Mn; Zn; non-uniform doping; photocatalysis