CuWO₄/CuS heterojunction photocatalyst for the application of visible-light-driven photodegradation of dye pollutions

Water pollution is a very serious problem concerning human health, and organic dyes are important pollution sources. Photocatalysts could convert light energy into chemical energy and photodegrade organic dyes. Thus, their potential use has been considered important. Herein, a copper-based heterojunction photocatalyst was developed through the hydrothermal method. In the heterojunction, two copper-based nanostructures, namely, nanodots CuWO₄ and nanorods CuS, were used to form a composite, and all products with different ratios showed better performance for the photodegradation of Rhodamine B (RhB), especially at the ratio of 1:1 (CuWS), which possessed the best photocatalytic efficacy. Narrow bandgap, large specific surface area and efficiency of the separation of photoexcited electrons and holes were the essential factors for the enhanced photocatalytic activity. Based on the analysis of the active species trapping experiments and electron spin resonance spectra, the photogenerated holes and •O₂^¯ were the essential active species during the photocatalytic degradation of RhB. Additionally, the sample CuWS could effectively photocatalytic degraded many other types of organic dyes under visible light and shows the great potential of application on environmental governance.