Improved photocatalytic performance of SiO2–TiO2 prepared with the assistance of SDBS

Highly photocatalytically active SiO2–TiO2 composite photocatalyst was prepared by sol–gel method with the assistance of sodium dodecylbenzenesulfonate (SDBS). The surface parameters, structure, morphology, the adsorption ability of light, the hydroxyl content and the photoinduced charge separation rate of the photocatalyst prepared (SDBS–SiO2–TiO2) were characterized by Brunauer–Emmett–Teller (BET) method, X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and surface photovoltage spectroscopy (SPS), respectively. The results reveal that SDBS alters the surface parameters, increases the hydroxyl content on the surface and greatly enhances the photoinduced charge separation rate. The photocatalytic activity of SDBS–SiO2–TiO2 for decolorization of methyl orange (MO) solution was evaluated, the result shows that the photocatalytic activity of SDBS–SiO2–TiO2 is fourfold of that the reference SiO2–TiO2 and the possible reason was discussed.

Graphical abstractIn general, the strong SPS response corresponds to the high separation rate of photoinduced charge carriers on the basis of the SPS principle. Thus, it can be confirmed that the SDBS–SiO2–TiO2 sample has a higher charge separation rate than the SiO2–TiO2 sample.Figure optionsDownload full-size imageDownload high-quality image (86 K)Download as PowerPoint slideHighlights► SDBS has been employed to fabricate SiO2–TiO2 photocatalyst. ► SDBS alters the distribution of the pore and increases of the hydroxyl content. ► The photoinduced charge separation rate has been enhanced. ► The photocatalytic activity has been greatly promoted.