CuS Nanoparticles Modified ZnO/CdS Dual Direct Z-type Heterostructure Nanocomposite for Efficient Visible-Light Photocatalytic Degradation RhB

Abstract

The low-temperature hydrothermal and water bath methods are used to manufacture CuS@ZnO/CdS catalyst. The Rhodamine B degradation rate constant of CuS@ZnO/CdS is around 1.53×10-2 min-1, which is 3.9 times greater than that of ZnO. The coupling of CdS and loading of CuS onto ZnO surfaces were evaluated using XRD, SEM, TEM, and XPS. SEM demonstrated that 5 mg of CdS was the most effective in controlling the shape of ZnO nanoflakes. Ultraviolet-visible absorption (UV-Vis) and Photoluminescence (PL) spectra reveal that CdS and CuS decreased the bandgap of ZnO and boosted its ability to absorb visible light. Transient photocurrent response (TPR) and electrochemical impedance spectra (EIS) display that CdS and CuS facilitate the quick separation of photoexcited carriers in ZnO. Notably, the optimal weight ratio of CuS was determined to be 15%, since excessive amounts of CuS would operate as recombination centers and cover active sites. Additionally, the dual Z-scheme carriers movement mechanism was proposed using sacrificed agent experiments. In this study, CuS@ZnO/CdS photocatalyst degraded RhB nearly 99% in 80 min, which is superior to the earlier photocatalysts. Therefore, this article holds great significance in practical application of metal chalcogenide-modified ZnO-based photocatalysts with superior visible-light-induced degradation performance in environmental purification.