Template-free synthesis of hollow microsphere CdS/ZnO heterojunction photocatalysts for photocatalytic hydrogen production

<p indent="0mm">Zinc-based composite spheres with good dispersibility were synthesised template-free via ethylene glycol and butanetetetrol-mediated synthesis using anhydrous zinc acetate as the zinc source, followed by calcination to obtain ZnO hollow microspheres. A series of CdS/ZnO composite photocatalysts were obtained by loading CdS nanoparticles with different mass ratios on ZnO microspheres by chemical precipitation. The experimental results show that the introduction of CdS successfully expands the light absorption range of ZnO microspheres, enabling the system to absorb more light energy for the subsequent reaction. Combined with the band gap, energy band potential and figure of merit obtained from the tests and calculations, it is found that the energy bands of CdS and ZnO are bent at the contact interface, and the electric field constructed therein assists the migration of photogenerated carriers.The formation of a compact Z-type heterojunction between CdS and ZnO enhances the separation efficiency of photogenerated carriers, providing a good guarantee for the photocatalytic reduction of hydrogen precipitation, which leads to a hydrogen production efficiency of the 2CZ composite samples under visible light irradiation of was 1558.85 μmol/g/h.