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.