Application of Ag/AgBr/GdVO4 composite photocatalyst in wastewater treatment.

Ag/AgBr/GdVO4 composite photocatalysts were designed and synthesized in this paper. The physical and chemical structures, as well as optical properties of the synthesized composite were investigated via XRD, XPS, TEM, and UV-vis. It is found that the composite showed a ternary heterojunction structure of Ag, AgBr and GdVO4. Meanwhile, it has a high intensity of light current, indicating its high separation efficiency of electron and hole. Photocatalytic oxidation of rhodamine B (RhB) under visible light irradiation was performed to investigate the activity of the Ag/AgBr/GdVO4 composite. Result indicates that it shows excellent photocatalytic activity. Under visible light irradiation for 12min, about 80% of RhB (30μmol/L) was degraded. The degradation rate is estimated to be 0.253 min-1, which is three times higher than that of pure AgBr. The high photoactivity can be ascribed to the synergetic effect of AgBr, GdVO4, and Ag nanoparticle in separation of electron-hole pairs.