Graphitic carbon nitride functionalized with Cu-doped Bi2S3 as a heterostructure photocatalyst for the visible light degradation of methyl orange

The combination of carbon-based materials with semiconductor nanoparticles of different structures promotes the unique properties that arise from the construction of heterojunctions. This improves the charge separation, and enhances the light absorption and steadiness of the composite. Thus, it offers a promising approach to achieving an efficient photocatalyst. In this study, the photocatalytic activity of graphitic carbon nitride and copper-doped bismuth sulphide heterostructure (g-C3N4/Cu–Bi2S3) obtained by the solvothermal method is reported. The prepared heterostructures were characterized to understand their morphological, optical, and electronic properties, and the photocatalytic activity for the degradation of methyl orange was studied. The formation of heterostructure between g-C3N4 and Cu–Bi2S3 led to a narrowing of band gaps compared to the pristine g-C3N4 and Cu–Bi2S3. Evaluation of the photocatalytic activity of the heterostructure showed about 95% degradation efficiency for methyl orange. The radical scavenging studies showed that superoxide radicals and photogenerated holes had the most significant impact on the photocatalytic process. The results confirm that the formation of the heterostructure of g-C3N4 with semiconductor nanomaterials offers a unique and facile route to enhancing the catalytic degradation of dyes.