Fabrication of NiS modified CdS nanorod p–n junction photocatalysts with enhanced visible-light photocatalytic H2-production activity

Abstract

Production of hydrogen from photocatalytic water splitting has become an attractive research area due to the possibility of converting solar energy into green chemical energy. In this study, novel NiS nanoparticle (NP) modified CdS nanorod (NR) p–n junction photocatalysts were prepared by a simple two-step hydrothermal method. Even without the Pt co-catalyst, the as-prepared NiS NP–CdS NR samples exhibited enhanced visible-light photocatalytic activity and good stability for H₂-production. The optimal NiS loading content was determined to be 5 mol%, and the corresponding H₂-production rate reached 1131 μmol h⁻¹ g⁻¹, which is even higher than that of the optimized Pt–CdS NRs. It is believed that the assembly of p-type NiS NPs on the surface of n-type CdS NRs could form a large number of p–n junctions, which could effectively reduce the recombination rates of electrons and holes, thus greatly enhancing the photocatalytic activity. This work not only shows a possibility for the utilization of low cost NiS nanoparticles as a substitute for noble metals (such as Pt) in the photocatalytic H₂-production but also provides a new insight into the design and fabrication of other new p–n junction photocatalysts for enhancing H₂-production activity.