Design of Dual-Modified MoS2 with Nanoporous Ni and Graphene as Efficient Catalysts for the Hydrogen Evolution Reaction

Molybdenum disulfide (MoS2), a two-dimensional layered material, has attracted ever-growing interest as one of the most promising non-noble-metal electrocatalysts for the hydrogen evolution reaction (HER). However, its catalytic efficiency is far from that of the best-performing Pt-based catalysts due to insufficient active sites and poor conductivity. Herein, density functional theory (DFT) simulations indicate that the catalytic activity of MoS2 could be improved through synergistic effects between the graphene substrate and Ni atom adsorption. Following this result, we designed and synthesized dual modified MoS2 nanosheets with nanoporous Ni and reduced graphite oxide, which show a low onset potential (85 mV), a small Tafel slope (71.3 mV dec(-1)), and a high cycling stability as HER catalysts. Both the DFT and experimental results demonstrate that the above superior performances are derived from a large number of edge active sites and fast electron transport. This study provides a comprehensive understanding of the HER activity of MoS2 and also a new strategy to design high-performance HER catalysts aided by DFT simulations.