▎ 摘　　要

Three dimensional (3D) hierarchical architectures based on molybdenum disulfide (MoS2) and reduced graphene oxide (rGO) are synthesized through a mixed solvothermal method. By simply increasing the amount of graphene oxide (GO) during the synthesis, the 3D assembly of MoS2 can be tuned from nanoflowers to cross-linked nanosheets firmly attached to rGO. The structural and compositional analysis show that MoS2 nanostructures in the hybrids are constituted by ultrathin nanosheets with single or a few layers, and the GO precursor is reduced as rGO simultaneously. Due to the synergetic effects of rGO nanosheets and controllable assembly in MoS2 ultrathin nanostructures, the resulting nanohybrids show optimized electrocatalytic hydrogen evolution properties in 0.5 M H2SO4 solution. This work provides a facile method to increase the efficiency of hydrogen production for MoS2 based materials and their analogues via a tunable bottom-up assembly strategy.