Z-scheme heterojunction of Bi2S3/g-C3N4 and its photocatalytic effect

Abstract

In this study, Bi₂S₃/g-C₃N₄ binary catalyst has been excellently prepared by a wet impregnation-calcination method to form Z-scheme heterojunction. The catalyst has been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS) and photoluminescence spectroscopy (PL). The physicochemical properties of the catalyst have been tested, such as crystal structure, morphology, optical properities, light absorption properties and luminescence properties. The results demonstrate that the photocatalytic activity is significantly increased when Bi₂S₃ with optimum weight percentage (5wt%) loaded into g-C₃N₄. Through photocatalytic degradation experiments, the optimal loading ratio, dosage and dye concentration of binary materials have been explored. At the same time, the effect of pH on the photocatalytic experiment under the optimal conditions is studied. Reactive blue 19 (RB19) is degraded by 97.77% in 2 h as the target pollutants. The trapping experiment further verified that ·O₂^- is the main active species in photocatalytic degradation of RB19.