Modification And Research Of Photocatalysis Application Of TiO₂ Mesoporous Nanomaterials

Serious environmental pollution and energy depletion are our major problem faced by all human beings all over the world. Scholars at home and abroad have done a lot of research work for the aspect of sewerage disposal, energy conservation. In recent years, due to its versatility in electrical, optical, chemical stability and photochemical properties, TiO2 nano material has been focused in many different wide applications, including air purification, sewage disposal, photocatalysts, solar cells, biomaterials, sensors, etc. In addition, due to its larger mesoporous pore volume and larger specific surface area, mesoporous titanium dioxide in the low dimensional TiO2 nanometer material can be used as a kind of very good photocatalytic material.But it only can absorb the sun’s ultraviolet part because of the bigger forbidden band width of TiO2 itself, and this causes lower utilization of sunlight. So improving its photocatalytic activity by doping modification becomes the primary solution.This article summarizes the structure, properties and light catalytic mechanism of TiO2 and research and application status of the low dimensional TiO2 nano material. Based on the predecessors’experience, we adopted the hydrothermal to prepare TiO2 nano materials and its related characterization and catalytic activity were characterized, then we discussed the influence of different hydrothermal conditions on its morphology. In addition, we doped mesoporous TiO2 nanometer powder with non-metallic S and rare earth element Ce/La. The specific research work and conclusions are as follows:(1) We prepared the low materials by alkali hydrothermal method and explored the hydrothermal conditions of preparing different morphology of TiO2 photocatalyst. At the same time the photocatalytic performance of the sample was also studied. Study found that within the range 125-155℃ could only prepare nano materials of mesoporous structure, and photocatalytic performance of mesoporous nano powder prepared under the conditions of the hot water temperature for 145℃ hydrothermal time for 48h is best. Just in 165℃,72h nanometer tubular morphology of TiO2 could be prepared. When the hydrothermal temperature continued to improve, that would occur nano rod and nanobelts morphology.(2) In the preparation conditions of more mature mesoporous nanometer powder above, we choose 145℃,48h for reference for the preparation of pure TiO2 nano powder. Then we doped nonmetallic S ion for mesporous TiO2 by hydrothermal method once again. Through characterization, we study thestructure and morphology and photocatalytic performance of the samples after doping, then determined the best S element doping amount.(3) Through constant temperature water bath deposition, mesporous TiO2 espectively doped with rare earth element Ce, La. We studied the photocatalytic performance of doped samples and discussed the optimal doping amount of two elements. The doping mechanism and the effects of the rare earth element on photocatalytic activity of the samples were discussed preliminarily.