Fabrication and characterization of Ag2CO3/SnS2 composites with enhanced visible-light photocatalytic activity for the degradation of organic pollutants

Abstract

Ag₂CO₃/SnS₂ composite photocatalysts with different Ag₂CO₃ contents were fabricated by a facile and efficient chemical precipitation method. The as-prepared samples were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectroscopy and photoluminescence spectroscopy. The Ag₂CO₃/SnS₂ photocatalyst displayed enhanced photocatalytic activity for the photocatalytic degradation of methyl orange (MO) under visible light irradiation (λ > 420 nm), and the optimum rate constant of Ag₂CO₃/SnS₂ at a weight content of 2.0% Ag₂CO₃ for the degradation of MO was 6.22 and 1.65 times as high as that of pure Ag₂CO₃ and SnS₂, respectively. Such an enhanced photocatalytic performance was predominantly ascribed to the synergistic effect between Ag₂CO₃ and SnS₂, which effectively facilitated interfacial charge transfer and improved photogenerated electron–hole pair separation efficiency. Furthermore, the superoxide radical anions (˙O₂⁻) and holes (h⁺) were considered as the main reactive species during the photodegradation process, and a synergistic photocatalysis mechanism between Ag₂CO₃ and SnS₂ was proposed based on the experimental results.