Enhanced photocatalytic performance of novel visible light-driven Ag–TiO2/SBA-15 photocatalyst

• Ag–TiO2/SBA-15 composite was successfully synthesized by two simple steps.
• Ag–TiO2 occupied the mesopore channels of SBA-15, preventing the aggregation.
• Ag–TiO2/SBA-15 showed higher absorption to the visible light than TiO2/SBA-15.
• Ag–TiO2/SBA-15 showed the effective separation of photogenerated electrons–holes.
• Ag–TiO2/SBA-15 showed enhanced visible photodegradation efficiency for RhB.

Ag–TiO2/SBA-15 composites were synthesized by two simple steps: firstly, TiO2 was inserted into the pore of SBA-15 by hydrolysis method, and then Ag was doped on the surface of TiO2/SBA-15 by the reduction of glucose. The as-prepared Ag–TiO2/SBA-15 composites were thoroughly characterized by X-ray diffraction, transmission electron microscopy with energy dispersion X-ray spectrum, X-ray photoelectron spectroscopy, N2 adsorption–desorption isotherms, UV–vis diffuse reflectance spectra and photoluminescence spectra. The photocatalytic activity was evaluated by photodegradation of Rhodamine B (RhB) under visible light irradiation. The experimental results indicated that Ag–TiO2/SBA-15 exhibited higher photocatalytic activity than that of P25 and TiO2/SBA-15, and could keep good stability. The significant enhancement in photodegradation activity might be ascribed to the combined effects, including enhanced reactant adsorption by the mesoporous structure of SBA-15, well distribution of TiO2 in the pores of SBA-15, and reduced electron–hole recombination rates due to Ag doping. In addition, a possible mechanism for the photodegradation process was proposed on the basis of active species scavenging experiments.

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