A construction of Ag-modified raspberry-like AgCl/Ag_2WO_4 with excellent visible-light photocatalytic property and stability

摘要

A novel multiphase photocatalyst of Ag-modified raspberry-like AgCl/Ag2WO4 composite was successfully fabricated via a facile solvent-free reaction technique, in which the Ag and AgCl were subtlely generated from the one-step reaction between Ag2WO4 particles and HONH3Cl as reductant and chlorine source at room temperature. The as-obtained ternary Ag-modified raspberry-like AgCl/Ag2WO4 composites can facilitate the contact of dye molecules and photocatalysts, exhibiting superior photocatalytic property and good recycling ability towards the decomposition of organic dye under the visible-light irradiation. The reductant addition amounts greatly affect the performance of Ag2WO4 photocatalyst. The optimum composite ratio of Ag-modified AgCl/Ag(2)WO(4 )samples show significant enhancement of visible-light photocatalytic activities and the degradation rate constant is about 16 times greater than that of pure Ag2WO4. The highly improved performance of Ag-modified raspberry-like AgCl/Ag2WO4 structure can be ascribed to the surface plasma resonance (SPR) effects of metal Ag and the synergistic effect among composites, accordingly effectively promote the separation of photoinduced electron-hole pairs, widen the absorbance range in the visible light and increase surface area. The h(+) and center dot OH degraded mechanism for the improved photocatalytic activity of Ag-modified AgCl/Ag2WO4 is proposed based on radical-trapping experiments and ESR spectra records.