The Synthesis Of TiO₂ Dopped With Sulfur And Research On Its Photocatalytic Activity

In recent years, environmental pollution problems such as water poluution is more and more serious, the people widely concerned these problems. Numerous studies have found that semiconductor photocatalytic oxidation technology is an effective, safe and non-two pollution solution in the aspect of water pollution control.In a word, people gives the TiO2 photocatalyst wide concern. This paper chose titanium sulfate as titanium source, using hydrothermal synthesis method to prepare TiO2 photocatalyst, paper discusses the influence law of the factors to the prepared catalyst, such as the hydrothermal time, the pH of precursor solution, proportion of the volume about ammonia, titanium concentration and hydrothermal temperature. Finally, this paper discusses the best process conditions of hydrothermal synthesis method and the influence law of the factors to the prepared catalyst. In order to make the TiO2 photocatalyst have effective uses of visible light, it is based on the best process conditions to explore the sulfur doping modified titanium oxide. Select Na2SO4、Na2S2O3、(CH3) 2SO (DMSO) as a doping agent, design a series of experiments, discusses the influences that the added amount of sulfur and the different valence state of sulfur to the photocatalytic performance, and the influences to the morphology of the sample. Finally, calcine the prepared TiO2 samples, discusses the calcination temperature on the performance of the sample. And using XRD, UV-vis, SEM, BET-specific surface area test and FTIR to analyze the structure, composition and appearance of the surface area. The rate of the degradation of methyl orange solution is used as the evaluation standard of the photocatalytic activity of TiO2 semiconductor. The results show that:1. The best process conditions of hydrothermal synthesis method are:the hydrothermal time is 12h, the pH of precursor solution is 6, the titanium concentration is 0.3mol/L, the proportion of the volume about ammonia is 1:3 and the hydrothermal temperature is 120℃.2. The TiO2 samples which are doped with sulfur have photocatalytic activity in the visible region. The added amount of sulfur and different kinds of sulfide as sulfur source have very obvious and different effects on the photocatalytic activity of TiO2.In addition, for different kinds of sulfide as a sulfur source of TiO2 samples, the influence law of calcination temperature on the crystal is different.