Noble-Metal-Free Visible Light Driven Hetero-structural Ni/ZnxCd1−xS Photocatalyst for Efficient Hydrogen Production

Abstract

Ni/ZnxCd1−xS composite photocatalyst was successfully synthesized by hydrothermal method and in situ photodeposition method, and certain hydrogen evolution results were obtained in acidic, neutral and alkaline sacrificial reagents. Among them, hydrogen evolution amount reached 11.993 mmol h−1 g−1 in alkaline Na2S/Na2SO3 solution. According to SEM, TEM and Mapping, two solid solutions of ZnxCd1−xS were formed under specific reaction conditions, which provided a large specific surface area and increased the contact area between metal Ni and ZnxCd1−xS, leading to more electron transfer. The UV–Vis diffuse reflectance spectra indicates that, due to the interface interaction between Ni and ZnxCd1−xS, the photodeposition of Ni leads to the reduction of the band gap of the photocatalyst, the expansion of visible light absorption range, and the generation of more photogenerated electrons. The excellent electron transport ability of Ni leads to the rapid separation of electron–hole pairs, inhibits the recombination of electron–hole pairs, and greatly improves the photocatalytic activity. This work describes the effective synergistic effect of Ni/ZnxCd1−xS photocatalysis, showing good hydrogen evolution effect, and emphasizes the excellent electronic conductivity without noble metal synergistic catalyst.