Preparation And Research On The Photocatalytic Activities Of New Semiconductor Photocatalysts

As the environment pollutions increasing all over the world, the environment purification have been attracted more attentions at home and abroad. Semiconductor photocatalysts have wide applications in the waste water treatment, air purification, bacillus resistance and self-cleanness. Semiconductor photocatalytic oxidative technology overcomes many disadvantages of traditional methods after its appearance. So it has become researching hotspot around the world. But low photocatalytic activity, low solar utilization and so on block the widely applications of the semiconductor photocatalytic materials. Recently, researchers all over the world are trying to find the methods or approach of decorating semiconductor photocatalysts all the time. In this paper, the photocatalytic activities are discussed from preparation of high BET (Brunauer-Emmett-Teller) surface photocatalyst, decorating and so on.In chapter 2, the main point is trying to prepare high photocatalytic activity, high BET surface and pure anatase nano TiO₂. Using TiO₂ as starting material, nano TiO₂ powder was prepared by hydrothermal method in this chapter. High photocatalytic activity and high BET surface TiO₂ was prepared by controlling the reactive temperature, the reactive time and the sol concentration. TiO₂ particle sizes were controlled by changing reactive conditions. So high BET surface nano TiO₂ could be easily synthesized. The photocatalytic activity of as-prepared nano TiO₂ was much higher than P25. It offers a new way to prepare high photocatalytic activity TiO₂.In chapter 3, to overcome the disadvantage of electron and hole easy recombination, the photocatalytic effects of MWCNTs and C₆₀ on TiO₂ were discussed. Using MWCNTs as support, the soluble C₆₀/TiO₂/MWCNTs nanocomposites were synthesized by hydrothermal method. The recombination of electron and hole is greatly decreased because of the good electronic conductivity of MWCNTs and C₆₀. So its photocatalytic activities could be greatly increased.In chapter 4, MWCNTs were doped to increase the photocatalytic activity of WO₃. The photocatalytic effects of MWCNTs on WO₃ were discussed. MWCNTs were put into the tungstate solution, and tungstate would be supported by MWCNTs or enter into the inner of MWCNTs. The WO₃/MWCNTs nanocomposites were got after calcining the mixture. The photocatalytic activities of WO3 were greatly enhanced because of the eminent electronic conductivity and adsorption.