CdS@Ni3S2/Cu2S electrode for electrocatalysis and boosted photo-assisted electrocatalysis hydrogen production

Abstract

Photo-assisted electrocatalysis (PA-EC) water splitting technology, which combines photocatalysis and electrocatalysis, has gradually become a research hotspot in the production of green hydrogen energy. Herein, for the first time, novel Cu/Ni alloy foam self-supporting CdS@Ni3S2/Cu2S core–shell nanorod arrays are prepared by a simple one-pot hydrothermal process. The CdS@Ni3S2/Cu2S exhibits both excellent electrocatalytic and photo-assisted electrocatalytic water splitting performance. During the long-time PA-EC water splitting test, the average H2 production rate reaches 568.1 μmol cm-2h−1, which is about 1.8 times higher than that of 284.1 μmol cm-2h−1 under dark condition. In addition, the electrical-to-hydrogen (ηETH) and solar-to-hydrogen (ηSTH) conversion efficiency reaches to be 97% and 8.9%, respectively. Mechanism investigation results show that during EC water splitting process, CdS nanorods mainly play as support material for the electroactive Ni3S2 and Cu2S. While, in the PA-EC process, CdS, Cu2S and Ni3S2 were photoexcited by light irradiation, and just as the presence of additional photogenerated electrons and holes, CdS@Ni3S2/Cu2S exhibits boosted photo-assisted water splitting properties. This work provides a new strategy for the construction of bifunctional photocatalysts combined with electrocatalysts in photo-assisted electrocatalysis overall water splitting.