Photocatalytic Degradation of Rhodamine B over Sulfated SiO2-TiO2 Composite by Sulphuric Acid Impregnation Method

Abstract

Abstract:Sulfate modified SiO 2 -TiO 2 photocatalysts with different SO 4 2− loadings were prepared by incipient-wetness impregnation method using H 2 SO 4 solution with various concentrations. The as-prepared SO 4 2− /SiO 2 -TiO 2 samples were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), BrunauerEmmett-Teller (BET) method, Uv-vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and terephthalic acid photoluminescence probing technique (TA-PL), respectively. The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic degradation of rhodamine B under ultraviolet light irradiation. The effects of H 2 SO 4 solution concentration on the structure, morphology, surface properties and photocatalytic activity of SO 4 2− /SiO 2 -TiO 2 samples were investigated. The results indicated that the catalyst prepared with 4 mol/L H 2 SO 4 solution, it showed the highest photocatalytic activity. The higher photocatalytic activity could be attributed to the improved surface properties and the enhanced separation rate of photoinduced electron-hole pairs.