Preparation And Modification Of Loaded TiO₂ And The Photocatalysis Properties

TiO2 photocatalyst materials are becoming the most widely studied and used photocatalyst to be applied in the degradation of organic pollutants due to their advantages of non-toxicity, chemical inertness, as well as environment friendly. But in the the practical applications of TiO2 photocatalysis technology, the problems of being difficult in separating and recycling TiO2 powders, low utilization rate of the sun are existent. In order to improve the photocatalytic of TiO2 as well as its recovery rate, this article has synthesized the supported TiO2 photocatalyst and adopted the method of ionic doping to modify the prepared catalysts. Details are as follows.In this article, TiO2/?-AlO3 and TiO2/diatomite composite photocatalysts were prepared by sol-gel method with tetrabutyl titnate as raw material, ?-Al2O3 and diatomite as carriers,.The prepared catalysts were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Differential Thermal Analysis and Thermal Gravimetric analysis(DTA-TG) etc. The results showed that the use of ?-Al2O3 and diatomite as carriers affected the TiO2 crystal transition temperature to some extent and improved its thermodynamic stability. Methylene blue was used as the simulated organic wastewater to observe the effect of calcination temperature, the mole ratio of Ti/Al, the mole ratio of Ti/Si and carriers to photocatalytic performance. The results showed:550? was the best calcination temperature for TiO2 photocatalyst. When n(Al):n(Ti)= 3 and calcination temperature was 550?, TiO2/y-Al2O3 had the better photocatalytic activity than the other conditions of preparation, and the degradation rate of methylene blue under the irradiation of UV for 3 hours was 95.7%. When n(Si):n(Ti)= 1 and calcination temperature was 550?, the degradation rate was 98.4%.Moreover, Mn+/TiO2-diatomite were prepared by impregnation and calcination method with TiO2/diatomite as the precursor, nitrate as M (M represents Fe, Cu, Zn, Co, La) source to observe the influence of metal species and doping content. The catalysts were characterized by XRD, SEM. We put the methylene blue solution under the irradiation of UV and visible light for 3 hours in order to observe the property of photocatalysis. The results showed:when the doping content of La was 1%, photocatalytic effect was the best.