Studies On Preparation And Doping Of Titanium Dioxide

In recent years, the technique of photocatalytic degradation of different pollutants in waste water has been studied. More and more scientists and researchers believe that the photocatalysis technique must be used into various fields, especially, in the area of environmental water resources protection, because its low energy expense, no secondary pollution and easy operation process etc. Some semiconductors such as TiO2,ZnO,CdS,WO3 etc. have been researched and used as photocatalysts into waste water treatment, therefore, much attentions have been paid to their preparation and chemically modification of these semiconductors.In this paper, the optimum preparation conditions of TiO2 photocatalyst and its activity of photocatalytic descomposition of phenol in waste water was described. The effects of doping metal ions on photocatalytic activity of TiO2 was studied.During the experiments, titanium dioxide particles were prepared by sol-gel method with Ti(OBu)4 introduced in the C2H5OH solution and inhibited by CH3COOH. Effects of amount of agent on gelation time and photocatalytic performances were investigated experimentally. Meanwhile, the influences of different sintering temperatures and sintering time on photocatalytic activity have also been discussed and the optimum preparation conditions were obtained. In addition, the crystal transition process of titanium dioxide powder has been characterized by the means of XRD.The photocatalystic oxidation mechanism of TiO2 and the doping process of modified TiO2 powder has been investigated. Based on the previous preparation conditions, we selected twelve ions ,such as Fe3+,V5+,Pb2+,Cr3+,Zn2+etc., as dopants and synthesized relevant titanium dioxide photocatalysts by the sol-gel process respectively. Furthermore, Effects of dopants on photocatalytic performances and composition, structure and particle size of have TiO2 been studied. The photocatalysis behaviour of doped TiO2 has been found.With the experimental results, we find out three metal ions Ag+,Mo5+, Fe3+ as the reasonable dopants for TiO2. Consequently, the optimum doping amount of metal ions the doping process of doped TiO2 have been established.