A novel ternary nano-photocatalyst (Ni/Ni3C/CdS) for HER and water purification with enhanced photocatalytic activity

CdS-based nanomaterials received much attention since it was synthesized and used as photocatalysts in HER reaction and degradations of organic pollutants. However, it is still an urgent issue to improve the stability and catalytic performance of these kinds of materials before they meet the requirements of the practical applications. Therefore, A novel nano-photocatalyst named as NC-15 was prepared in this paper by loading Ni3C nanosheets (NSs) and Ni nanoparticles (NPs) to the surface of CdS nanowires (NWs). Using a 300 W Xe-lamp (≥400 nm) as the illumination source, NC-15 could accelerate the H2-evolution reaction (HER) in aqueous solution of lactic acid (10 vol%) with the rates of 15247 μmol·g-1h−1 which is ca. 381-time higher than that of CdS NWs, and OTC (LEF) could be ca. 91 % (89 %) degenerated as its aqueous solution (40 ppm) were irradiated 60 mins. The electrochemical analysis indicates that NC-15 should be an n-type semiconductor with the overpotential of −1.08 V vs. Ag/AgCl, which is much lower than those of CdS NWs (-1.20 V), Ni3C/CdS (-1.18 V) and Ni/CdS (-1.13 V) and indicates a faster-photogenerated electrons transfer rate of NC-15. The theoretical simulations confirm that the Ni NPs should supply the active sites during the photocatalytic procedure and the internal electric field at the interfaces of CdS/Ni3C and Ni3C/Ni could accelerate the photogenerated carriers’ separation and migration. In a word, CdS-based ternary nano-photocatalysts possess great potential in the practical application of HER and photodegradation reactions.