The Developments of Nano-photocatalytic Degradation in Dye Pollution
ZHANG Tian-yong ZHU Dan-dan FU Qiang ZHAOJin-cai (Department of Fine Chemicals and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072; Key Laboratory of Photochemistry, Molecular Science Center, Institute of Chemistry, Chinese Academy of Science, Beijing 100080)
The developments of photocatalytic oxidative degradation of dye pollutants in the presence of TiO2 were reviewed with 26 references. The major factors of photocatalytic reaction, destructive pathway of dye molecules as well as the degradation mechanism of dyes were discussed. Of all the catalysts, TiO2 was the best and widely used for investigation and development. Effects of pH on photocatalysis depend on the chemical constitution and physico-chemical properties of the dye pollutants. Usually, the addition of photoexcited-electron scavenger could greatly accelerate the rate of photocatalytic degradation. Surfactants would also provide certain influences on photocatalysis because of its amphophilicity (hydrophilic and lipophilic) of the surfactant, and consequently, it would play an important role for the determination of dissolution, dispersion and adsorption of dyes. Reaction temperature had little effect on Photocatalytic rate.