Multi-interfacial engineering of hierarchical CoNi2S4/WS2/Co9S8 hybrid frameworks for robust all-pH electrocatalytic hydrogen evolution

Water dissociation, hydroxyl desorption, and hydrogen recombination are three major prerequisites for all-pH hydrogen evolution reaction (HER). Herein, a multi-interfacial engineering in hierarchical CoNi2S4/WS2/Co9S8 (NiCoWS) hybrid frameworks was developed. The NiCoWS is composed of highly exposed active sites and abundant heterogeneous interfaces. The NiCoWS exhibits small overpotentials of 70 mV, 61 mV, and 146 mV at 10 mA cm(-2) in alkaline, acid, and neutral medium, respectively, for HER. The robust performance of NiCoWS should originate from the collective synergy of special morphological, electronic, and interfacial structures. The hierarchical nanosheet framework can facilitate the transport of charge/mass as well as the exposure of more active interface sites. Density functional theory (DFT) calculations verify that the multi-interfacial engineering in NiCoWS can endow the electrocatalyst with enhanced electrical conductivity and favorable adsorption energies of H*, H2O* and H center dot center dot center dot OH*.