无氧条件下TiO_2薄膜界面光催化反应的XPS研究

XPS Study on Interface Photocatalytic Reaction of TiO_2 Film in the Absence of Oxygen

设计利用X射线光电子能谱仪的高真空系统作为无氧条件下光催化反应和分析的场所,研究真空无氧环境和大气有氧环境中紫外光激发TiO2薄膜表面的光催化反应,并对无氧条件下TiO2薄膜降解亚甲基蓝进行初步探索.结果表明,在大气有氧和真空无氧条件下TiO2薄膜经紫外光照后,表面的化学组成和化学状态均发生了变化;在有氧环境中TiO2薄膜表面氧含量增加,而在无氧环境中TiO2薄膜表面氧含量减少.TiO2薄膜表面的吸附氧是维持无氧条件下光催化反应的重要原因,增加薄膜表面吸附氧的含量能提高TiO2薄膜在无氧环境中的催化活性.此外,无氧条件下TiO2薄膜降解亚甲基蓝光催化反应过程中,亚甲基蓝分子只是脱去了某个含氮的基团,生成了中间产物,而并没有完全降解.

The vacuum system of X-ray Photoelectron Spectroscopy was used as the place of photocatalytic reaction in the absence of oxygen, and the interface photocatalytic reaction of TiO2 film excited by ultraviolet ligh in the absence of oxygen and in the presence of oxygen （ air ） were studied using X-ray Photoelectron Spectroscopy. The result shows that the TiO2 film has photocatalytic activity under high vacuum and it is very important for the oxygencontaining groups on TiO2 film to maintained photocatalytic reaction in the absence of oxygen. Meanwhile, the photocatalytic reaction that TiO2 film degraded methylene blue under high vacuum was also researched preliminarily, the result displays that the methylene blue molecule has been just removed a certain nitrogenous group to form the intermediate products during the photocatalytic reaction process, so it can not be degraded totally.