▎ 摘　　要

Modified bimetallic chalcogenides with numerous active sites of appropriate structures for extensive water splitting in alkaline hydrogen evolution reaction (HER) are quite challenging. In this study, we have designed a graphene nano-sheet anchored NiS2/MoS2 heterostructure through a facile two-step method and have employed them towards HER. To evaluate the performance of the NiS2/MoS2 @GNS, The crystalline phase, morphology and material purity are evaluated by XRD, SEM, high resolution transmission microscopy HR-TEM and EDS. In addition, the electrochemical performance of the as-synthesized NiS2/MoS2 @GNS composites and other electrocatalysts are tested towards the HER in 1 M KOH electrolyte. It is noted that the graphene nano-sheet (GNS) anchored NiS2/MoS2 composite shows an excellent electrocatalytic activity with a less overpotential of 130 mV at current density (vertical bar j vertical bar) of 10 mA cm(-2) and a low Tafel slope of 40 mV dec(-1) compared with pristine NiS2/MoS2 material (141 mV at 10 mA cm(-2) and Tafel slope of 48 mV dec(-1)). Furthermore, it possessed good stability for 1000 cycles and performed time-dependant current density for 10 h at a limited overpotential of 130 mV. The high synergistic effect between NiS2/MoS2 and GNS in promotion of hydrogen (H-2) generation efficiency is ascribed to more active sites, low charge transfer resistance and great electrochemical kinetics which justified the use of NiS2/MoS2@GNS hybrid material as a best alternative to replace noble metal for efficient HER.