▎ 摘　　要

Two-dimensional molybdenum disulfide has great potential to replace rare precious metals for hydrogen evolution reaction. Herein, we report a one pot assembly strategy for in situ growing vertical embedded MoS2 nanocrystals on graphene surface. The resultant sandwiched architecture could not only expose more active sites within MoS2 edge but also reduce stacking tendency of the layer-structured graphene support, leading to a significant improvement in HER performance. The materials showed an overpotential of 142 mV at 10 mA.cm(-2) and a Tafel slope of 68 mV.dec(-1), which are among the best results ever obtained by the similar materials. Moreover, this method is facile, environmentally friendly, and suitable for mass production, making it attractive for practical applications.