Enhanced visible-light photocatalytic activity of Ag/In₂S₃ photocatalysts induced by Schottky contact and SPR of Ag

In this work, a highly photocatalytic Ag/In₂S₃ was synthesized via the hydrothermal and photoreduction method. The as-prepared photocatalysts were confirmed by XRD, SEM, HRTEM, and XPS showing that Ag nanoparticles were decorated on the In₂S₃ surface. Photocatalytic activities of photocatalysts were investigated for photodegradation of methyl orange (MO) under visible light. The Ag/In₂S₃ composites showed the enhanced photocatalytic efficiency of 97% under visible light irradiation for 90 min, which was about 3.0 times higher than that of pure In₂S₃. The enhanced photocatalytic performance could be owing to the SPR of Ag and the Schottky junction formed between Ag and In₂S₃. Our PL results indicate the inhibited recombination of the photogenerated electron–hole pairs in In₂S₃ upon the attachment of Ag nanoparticles. The active species tests demonstrate that the superoxide radical (·O²⁻) and h⁺ are responsible for the efficient degradation of MO over Ag/In₂S₃. In addition, it also proposes a potential mechanism for enhancing the photocatalytic activity.