Modification to Promote Visible-Light Catalytic Activity of TiO2

As an environmentally friendly pollution management technology, TiO2 photocatalytic technique has a great potential for application as catalysts in the purification of waste water and exhaust gas, the sterilization and environment protection. However, its large energy band gap limits the practical application in the case of natural solar light. The development of visible light responsive TiO2 is one of the most important subjects of the research. The domestic and foreign modifications of TiO2 photocatalysts have improved steadily and diversely. In this paper, the development and mechanism of TiO2 photocatalysis are reviewed. The methods for promoting the visible light photocatalytic activity of TiO2 including metal doping, surface deposition of precious metals, semiconductor coupling, nonmetal doping, metal complex and dye sensitizing are discussed, all of which can allow for a UV-light activated photocatalytic reaction under visible light. In addition, some examples are cited, which indicate that the highlight for improving the photocatalytic efficiency is the modification of TiO2. Finally, the prospects and existing problems of TiO2 photocatalysis technology are also addressed.