Synthesis And Photocatalytic Property Of Ag Doped TiO₂/SBA-15Catalyst

With the rapid development of the global economy and the rapid expansion of theindustry and agriculture, the problems of environmental pollution, especially waterpollution problems, are becoming more and more serious. The emissions of organicdyes in textile industry are one of the main sources of water pollution, which attractedthe attention of people. Therefore, to find an efficient and economic method for thedegradation of sewage is in the imminent.TiO2was the most widely studied material because of its high photocatalyticactivity, stability and non-toxicity. However, the large band gap of TiO2(3.2eV)seriously limited its utilization of the solar spectrum. Therefore, many strategies havebeen devoted to the development of TiO2-based visible light photocatalysts, such asmetal or noble metal doping, and being loaded onto some supports. Moreover, it can befound that the noble metal Ag extended the spectral response of TiO2well into thevisible region and improved photocatalytic performance under visible light. AndSBA-15is a kind of mesoporous molecular sieve, with a highly ordered hexagonalstraight pore structure, and it has a higher hydrothermal stability and adsorptivity, whichhas a lot of advantages than other supports.Therefore, in this paper, SBA-15was chosen as the support, and TiO2/SBA-15composite was prepared by hydrolysis method. In order to enhance visible lightresponse, Ag nanoparticles were coated on the surface of TiO2/SBA-15to obtainAg-TiO2/SBA-15composites by the reduction of glucose.The as-prepared Ag-TiO2/SBA-15composites were characterized by X-raydiffraction (XRD), Transmission electron microscopy (TEM), Energy dispersion X-rayspectrum (EDS), N2adsorption-desorption isotherms, X-ray photoelectron spectroscopy(XPS), UV-vis diffuse reflectance spectra (DRS) and Photoluminescence spectra (PL).The photocatalytic activity was evaluated by photodegradation of Rhodamine B undervisible light irradiation, and5.0%Ag-TiO2/SBA-15was found to be the best catalyst. Aconceivable mechanism for the photodegradation process was proposed on the basis ofactive species scavenging experiments. In addition, the experimental results indicatedthat Ag-TiO2/SBA-15exhibited higher photocatalytic activities than that ofTiO2/SBA-15, Ag-SBA-15and Ag-TiO2, and could keep great stability.