Effect of activated carbon on the photocatalytic activity of CuInS2 in aqueous solution under visible light irradiation
摘要
In this study, CuInS2 (CIS) was prepared using the liquid phase reflux method, and different amounts of activated carbon (AC) are loaded onto CIS via a wet grinding method to prepare AC/CIS composites with varying composite ratios. The crystal structure, surface elemental composition, oxidation states, morphology, specific surface area, and optical properties of CIS and AC/CIS were analyzed ussing techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Brunauer–Emmett–Teller (BET) analysis, photoluminescence (PL), and ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis-DRS). Rhodamine B (RhB) was used as a model pollutant to investigate the visible-light photocatalytic activity of CIS and AC/CIS. The optimal mass load ratio for AC was determined to be 3%. At this optimal ratio, AC/CIS demonstrated the capability to degrade 80% of RhB within a span of 2 h. The judicious incorporation of AC enhances the visible light absorption of CIS, accelerates electron migration, which facilitates the separation of photogenerated carriers, thereby increasing the visible-light photocatalytic activity and recyclability stability of CIS. Additionally, due to the electrophilicity of AC, the introduction of AC led to a transformation in the main active species during the photocatalytic process, changing from holes (h+) and hydroxyl radicals (·OH) to superoxide radicals (·O2−). These findings strongly suggest that AC/CIS holds great promise as a visible photocatalyst for effectively degrading pollutants in the environment.