All-solid-state Z-scheme BiOX(Cl, Br)-Au-CdS Heterostructure: Photocatalytic Activity and Degradation Pathway

Abstract The disadvantage of CdS prone to photocorrosion limits its application in photocatalysis. In this work, we have prepared BiOX(Cl, Br)-Au-CdS photocatalyst with Z-scheme band structure by progressively deposition of Au and CdS. The XRD, TEM and SEM shows that Au nanoparticles were deposited by photodeposition on the BiOX nanosheets. Subsequently, the CdS in-situ deposition on Au nanoparticles due to the strong S-Au interaction. The Z-scheme BiOX(Cl, Br)-Au-CdS showed better visible-light-driven photocatalytic activity than BiOX, BiOX-Au toward the degradation of cationic dye Rhodamine B. The radical trapping experiments indicated that OH, h+ and O2− are the main reactive species responsible for the degradations of organic pollutants over BiOX(Cl, Br)-Au-CdS. Furthermore, the Z-scheme structure of BiOX(Cl, Br)-Au-CdS was confirmed by photoelectrochemical measurements and band potential calculation. Based on the combination of liquid chromatography and mass spectroscopy (LC–MS), a photocatalytic degradation pathway of rhodamine B was proposed. As a high visible-light-driven activity catalyst, BiOX(Cl, Br)-Au-CdS can be potentially used in pollutant removal and environmental remediation.