Preparation And Research Of Composite Nano Titania

In this paper, TiO2was prepared by sol-gel method using tetra-n-butyl-titanate as a precursor, in the orthogonal test, using temperature, water, alcohol and acid to optimize the technology, in which the factor of water is important, when the temperature is25℃, the molar ratio of tetra-n-butyl-titanate, water, ethanol and sulfuric acid is1:2:30:0.25, the particle size of TiO2is minimum. TiO2was prepared using nitric acid or sulfuric acid as acidity regulator in normal temperature, The products were characterized by FT-IR, XRD, SEM and BET, TiO2calcined are all anatase phase at500℃, TiO2/NO3-shows a particle size of15nm and specific surface area of37.77m2/g, whereas TiO2/SO42-shows a particle size of8nm and specific surface area of68.32m2/g. particle size of TiO2/SO42-is less than lOnm. but The specific surface area is almost2times than TiO2/SO42-. Photocatalytic degradation of methylene blue by experiment, TiO2/SO42-catalytic activity is better than that of TiO2/SO42-and remain unchanged in alkaline conditions, it means that the application ofTiO2/SO42-is more widely.TiO2films were prepared by impregnation, and characterized by XRD and SEM. load capacity of TiO2film increased As the load number, the most load of stainless steel net is6mg/cm2, when the load number is more than2, TiO2films will peel, drop and crack. The most load of Nickel foam is12mg/cm2, and optimum load number is3, the stability of TiO2film calcined at500℃substantially improve, and the load is2times more than its. The using of stainless steel carrier and nickel foam carrier did not affect TiO2anatase type, nickel foam supported TiO2film appeared NiO which can stop electronic carrying to carrier by calcination, and improve the photocatalytic activity. So the nickel foam carrier is better than that of stainless steel net.The modification research of TiO2/SO42-. we have studied its light response range and mechanism by doping Ag+,Fe3+, MgF2and LiF. using UV-VIS. Photocatalytic degradation of methylene blue by experiment, studying on photocatalytic activity of composite catalyst. The composite catalyst does not change the crystal from TiO2/SO42-, XRD show the diffraction intensity decreases, and the main diffraction width becomes larger, it means that the dopant ions replace part of Ti into TiO2/SO42-lattice, Analysis of composite catalysts by ultraviolet visible absorption spectroscopy, all of the doped and modified TiO2/SO42-are responsive to the visible light, in which Fe3+doped and modified is the most obvious, its absorption edge wavelength is500nm, followed by LiF and MgF2, last by Ag+The photocatalytic degradation of methylene blue solution, studying on photocatalytic activity of composite catalyst. When pH>7, MgF2-TiO2/SO42-catalyst degradation rate reaches95%, but the Fe3+-TiO2/SO42-catalyst degradation rate reaches92%. The higher initial concentration of methylene blue, the smaller degradation rate of composite catalyst, the best concentration is10-30mg/L. The catalyst photocatalytic activity of MgF2-TiO2/SO42-is better than that of Fe3+-TiO2/SO42-, but need to light1hours than Fe3+-TiO2/SO42-...