| Nowdays, environmental pollution menaces human being's living and limits the social development. Studies on the functional materials for environmental protection have been stressed. Nanometer TiO2 photocatalyst, as a new functional material for environmental protection, has been studied for about ten years. It can treat waste water and exhaust gas, kill bacteria and viruses. So it can be used to treat waste liquids, purify air, and so on. In a word, TiO2 has a wide application prospect. However it's such problems as relaying on ultraviolet radiation, efficiency, and lifetime in TKVs use limit it's application.In this paper, pure Fe3+-doped, and Fe3+/Zn2+-doped nanocrystalline TiO2 photocatalysts were prepared by Sol-Gel processes. The composition, micro-structure and properties of the prepared TiO2 powders were characterized by DTA-TG, XRD, TEM, XPS, FT-IR, spectrophotometer, and so on. The factors influencing TiO2 photocatalystic properties were discussed.Results showed that TiO2 crystalline diameters were in the range of 5-30nm. Conglomerations of powders in lower temperature were smaller than that in higher temperature. Grain diameters were in the range of 20-90nm. TiO2 crystal's superficial areas were in the range of 50-100m2/g. Iron and zinc doping can lower the transformation temperature of anatase to rutile. Photocatalytic activity was evaluated by the degradation of methlic in the sun. The Ti02 Powders doped with Fe3+at%=20% and Fe3+/Zn2+at%=50%(sintering at 300 C for 1h) have higher photocatalytic performances than that of the Ti02 powder doped with Fe3+at%=20%(sintering at 300 癈 for 3h). All of their degradation rate excess 90% and greater than that of Degussa P25. When the content of rutile in the crystalline studies was about 52%, the photocatalytic performances showed the hightist photocatalytic performance.
|
PDF Full Text Request