Preparation And Properties Of TiO 2 And Bi - Based Photocatalysts

Photocatalytic degration of organic pollutants in water has been attracted some attations due to the advantages of environment-friendly, simplicity and high efficience. TiO2as a classical photocatalyst has some disadvantages such as narrow range of light adsorption and particle aggregation. In addition, it has been reported that the morphology of photocatalysts has influence on their photocatalytic activity.Therefore, some techniques are used to dissolve these problems in this work. For example, the range of light adsorption is widen by doping Bi into crystal lattice of TiO2; the dispersity of nano TiO2is improved by loading TiO2on mesoporous carbon; to clarify the relationship between photocatalytic activity and morphology, carbon nanotube inserted of Bi nanocrystals in its tube will be prepared.Bi doped mesoporous TiO2is prepared by hard-template method, mesoporous carbon loaded TiO2is successfully synthesized with soft-template method, and carbon nanotue inserted of Bi nanocrystals in its tube is prepared in situ AAO template method. The crystal structure and morphology of the resultant products are characterized with X-ray diffraction, transmission electron microscope, scanning electron microscope, photoelectric spectrometer, physical adsorption instrument and UV visible spectrophotometer. Photo-degration of RhB is used as probe reaction to measure the catalytic activity of these products.The results show that the range of light adsorption is widen to550nm by Bi adoping TiO2, which endows TiO2with visible light absorption, and99%degration efficience of RhB is achieved with Bi adoped TiO2as catalyst after modulated sunlight irradition for160min. A good dispersity of TiO2nanoparticles is obtained after they are loaded on the surface of mesoporous carbon. Moreover, the high surface area of mesoporous carbon is very helpful for adsorping the dye of RhB. With the cooperative action of TiO2catalysis and mesoporous carbon adsorption,100%degration efficience of RhB is got after modulated sun light irradition for60min. Few of literatures had reported the photocatalysis of Bi nanoparticles. In this work, a facile in situ template carbonization method was developed to prepare bismuth nanocrystal-filled carbon nanotubes (Bi-CNTs), in which monodispersed Bi nanocrystals with size of3-5nm are filled in carbon nanotube with diameter of100nm. The resultant Bi-CNTs exhibited high photoactivity for the Rhodamine B (RhB) degradation under UV irradiation, and the degradation efficiency was up to96.6%after120min.