Catalysts for hydrogen evolution in universal-pH medium: Construction and structural optimization of Ni3S2/Co9S8/WS2 interface synergies

The performance of heterostructure nanomaterials depends on both the individual components characteristics and the interfaces synergistic effect. In this paper, a high-activity universal-pH HER catalyst, Ti felt supported nanoporous Ni3S2/Co9S8/WS2 (NiCoW-S) is synthesized by electrodeposition and vulcanization. Compared with Ni3S2/Co9S8, Ni3S2/Co9S8/WS2 heterostructure catalyst exhibits enhancement of intrinsic catalytic active center, charge transfer rate and stability in a wide pH range. Benefiting from the 3D porous structure and high-density heterostructure active edge sites, NiCoW-S shows good stability. And Moreover, it only needs 35 and 145 mV to reach 10 mA cm-2 in 0.5 M H2SO4 and 1.0 M KOH, respectively. Based on the experimental analysis, the favorable synergistic effect of metal components and the formation of sulfur vacancies can enhance the conductivity of electron transfer, which promotes electron transfer at the active heterogeneous interface. It provides a reference for designing of advanced metal sulfide heterostructure for hydrogen production in the future.