Microwave Heating Preparation of Ag-modified TiO_2 for Photocatalytic Degradation of Gaseous Toluene

Using Ti(OBu)4 as titanium source,Ag-modified TiO2 was prepared by the microwave heating method and the hydrothermal method,respectively,and was characterized by X-ray diffraction(XRD),X-ray fluorescence(XRF),ultraviolet-visible diffuse reflectance spectroscope(UV-Vis) and scanning electron microscope(SEM).The photocatalytic activity of the samples was tested in the degradation of gaseous toluene under UV and visible light irradiation,respectively.The results showed that the presence of Ag promoted the phase transformation of TiO2 from anatase to other phases.Compared with the hydrothermal method,the microwave heating method had more positive effect on the formation of Ag-modified TiO2 with smaller crystallite size(16.4nm) and aggregate(80-200nm),more phases structure(anatase,rutile and brookite),richer channel structure,and lower band gap energy(2.87eV).Furthermore,Ag-modified TiO2 prepared by the microwave heating method exhibited a better photocatalytic activity in the degradation of toluene under UV or visible light irradiation.