Enhanced visible Light-Driven photocatalytic hydrogen evolution and stability for noble Metal-Free MoS₂/Zn_0.5Cd_0.5S heterostructures with W/Z phase junctions

A series of composite heterojunction-MoS₂/Zn_0.5Cd_0.5S photocatalysts free of noble metal ions was prepared using a simple hydrothermal method. The X-ray diffraction spectra of the MoS₂/Zn_0.5Cd_0.5S composites exhibit three strong intensive peaks, thereby explaining the existence of wurtzite (CdS) and zinc blende (ZnS) in the form of the wurtzite/zinc-blende phase junctions. Microstructural studies indicate that the sample displays a typical cubic crystal structure and that the MoS₂ with flower-like structure uniformly wraps the granular Zn_0.5Cd_0.5S. X-ray photoelectron, Fourier transform infrared, and UV–Vis diffuse reflectance spectroscopic methods confirm that the heterojunction, which possesses outstanding photoresponse ability, is constructed between Zn_0.5Cd_0.5S nanoparticles and MoS₂ nanoflowers. The fluorescence spectroscopy, surface photocurrent spectroscopy, and electrochemical studies indicate that Zn_0.5Cd_0.5S nanoparticles with specific amount of MoS₂ nanoflowers can effectively suppress the recombination of photoinduced charge carriers of the composites. Therefore, pristine Zn_0.5Cd_0.5S nanoparticles loaded with 3%MoS₂ exhibit optimum performance of hydrogen production (388.2 μmol/h), which is 1.3 times that of pristine Zn_0.5Cd_0.5S nanoparticles. A plausible mechanism for enhanced photocatalysis is provided in terms of the heterojunction assisted effective separation of charge carriers that are generated by irradiation.