FeNi@N-doped Graphene Core-Shell Nanoparticles on Carbon Matrix Coupled with MoS2 Nanosheets as a Competent Electrocatalysts for Efficient Hydrogen Evolution Reaction

Synthesis of noble-metal-free electrocatalysts for green hydrogen production is crucial to overcoming the energy demand of modern society. One of the most competitive and alternative noble-metal-free electrocatalysts for HER is Molybdenum disulfide (MoS2) based composites. Herein, MoS2 nanosheets grow on FeNi@N-doped graphene nanoparticles/N-doped carbon matrix (FeNi@NG/NCM@MoS2), using the hydrothermal method. FeNi@NG/NCM@MoS2 hybrid displays outstanding HER performance with a low overpotential of 79 mV at 10 mA cm-2, a small Tafel slope of 40.2 mV dec-1, and high durability. First-principles density functional theory (DFT) simulations confirm the electron transformation from FeNi alloy to NG surface of FeNi@NG particle and subsequently further transfer to MoS2 nanosheets which decrease the Gibbs free energy (ΔGH* ≈ -0.08 eV) and local work function for enhanced HER activities. Our work highlights the understanding of electron transfer in demonstrating the kinetic reaction of the HER process and offers a new avenue for constructing efficient MoS2-based electrocatalysts.