| In recent years, among the numerous photocatalytic materials, titanium dioxide has become widely used photocatalyst, which is due to its advantages such as low-cost, non-toxic, chemical stability and higher photocatalytic activity. Many disadvantages of titanium dioxide appeared at the same time, such as its narrow range of photoresponse, less surface area,and hard reuse of the photocatalyst, which restrict the development of titanium dioxide. The most effective and fast solution to overcome these disadvantages are surface loading and modification.In this text, chromium/sulfur co-doped TiO2 supported on Silicon dioxide（SiO2）, Hollow glass microspheres（HGM） and Zeolites and molecular sieves-5（ZSM-5） were synthesized by sol-gel method, and prepared Cr/S/TiO2-SiO2, Cr/S/TiO2-HGM and Cr/S/TiO2-ZSM-5 photocatalyst. Phase, morphology, purity, surface area and optical adsorption properties of samples were investigated by XRD, SEM, EDX and UV-Vis DRS spectra. The effects of the different calcination temperature, calcination time, photocatalysts amount and cycle times on the photocatalytic activity were studied. Their photocatalytic activities were evaluated by degradation of indigo carmine.The results indicated that the synthesized Cr/S/TiO2-SiO2, Cr/S/TiO2-HGM and Cr/S/TiO2-ZSM-5 have a higher specific surface area, a better reutilization than TiO2 and Cr/S/TiO2. Also the photocatalytic activity of TiO2 under visible light irradiation was improved. The conclusion was drawed by indigo carmine degradation, the optimal calcinations time and the optimal temperature for Cr/S/TiO2-SiO2, Cr/S/TiO2-HGM and Cr/S/TiO2-ZSM-5 were 500 ℃ and 2 hours. While the aging time and the dose of Cr/S/TiO2-SiO2, Cr/S/TiO2-HGM and Cr/S/TiO2-ZSM-5 were 1 h, 2 h, 1 h and 3.0 g/L, 3.0 g/L, 2.0 g/L. The photocatalysts can degrade indigo carmine totally in 80 min.
|
PDF Full Text Request