Growth of MoS2 nanosheets on M@N-doped carbon particles (M = Co, Fe or CoFe Alloy) as an efficient electrocatalyst toward hydrogen evolution reaction

The design and synthesis of a highly active noble metal-free electrocatalyst for hydrogen evolution reaction (HER) from water splitting are crucial for renewable energy technologies. Herein, we report the growth of molybdenum disulfide (MoS2) on N-doped carbon encapsulated metal particles (M@NDC@MoS2, where M = Co, Fe or CoFe alloy) as a highly active electrocatalyst for HER. The hierarchical MoS2 nanosheets are grown on M@NDC using the hydrothermal method. Our results show that CoFe@NDC@MoS2 hybrid spheres exhibit excellent HER performance with an overpotential of 64 mV at a current density of 10 mA cm-2 and a small Tafel slope of 45 mV dec-1. In addition, CoFe@NDC@MoS2 hybrid spheres have good long-term stability and durability in acidic conditions. Besides, density functional theory (DFT) simulations of the proposed catalysts are performed and suggest that the superior catalytic activity of CoFe@NDC@MoS2 is due to the optimal electron transfer from CoFe@NDC nanoparticles to MoS2 nanosheets. This electron transfer facilitates H+ interaction and adsorption, leading to a decreased Gibbs free energy (Delta GH* approximate to 0.08 eV) and local work function on the surface, which consequently enhances the HER performance.