Construction of Ag2S/Ag3VO4 Heterojunction by Partial Sulfidation Technology for Visible-light-driven Photocatalytic RhB Degradation

Abstract

Photocatalytic technology is one of the most promising technologies for wastewater treatment. In this study, an Ag₂S/Ag₃VO₄ heterojunction was prepared by combination of in-situ partial sulfidation and hydrothermal technologies. The photodegradation results demonstrated that the highest removal efficiency for RhB was 96% for 40%-Ag₂S/Ag₃VO₄ heterojunction in 6 min under visible light irradiation, which was obviously superior to that of pure Ag₃VO₄ (∼46% in 6 min) and Ag₂S (∼1.8% in 6 min) photocatalysts. As manifested by the DSR experiment, the improved photodegradation ability of the 40%-Ag₂S/Ag₃VO₄ heterojunction was attributed to enhanced light absorption and excellent electron-hole pairs separation induced by the formation of a Z-scheme heterojunction between Ag₂S and Ag₃VO₄. The active species capture experiments confirmed that h⁺ plays the important role for degradation of RhB. Furthermore, the results of photodegradation cyclic test revealed that the 40%-Ag₂S/Ag₃VO₄ heterojunction owned an excellent photocatalytic stability.