▎ 摘　　要

The construction of a less expensive and highly effective electrocatalyst for using in electrochemical hydrogen evolution reaction (HER) play a decisive role in terms of renewable hydrogen energy. Among them, transition metal compounds are the indispensable part for the development of electrocatalysts, which has important importance that cannot be ignored. Here, the cobalt sulfide monomer were separately embedded in the surface and intermediate layer of reduced graphene oxide (RGO) and nitrogen-doped reduced graphene oxide (N-RGO) by a novel and simple method. The presence of CoS nanoparticles hindered redeposition of the N-RGO layer and increases the space between the layers, which effectively improved the electrochemical performance of the catalysts. Excellent electrochemical performance is shown as a low onset potential of -50.3 mV, a low Tafel slope of 74.4 mV/dec, and a high double layer capacitance of 9.8 mF cm(-2), which is superior to most CoS catalysts. In addition, CoS/N-RGO nanocomposites have good stability under acidic conditions. The novel and simple preparation method provides a reference for the preparation of low-cost electrocatalysts having excellent HER properties.