Edge-oriented MoS2 supported on nickel/carbon core–shell nanospheres for enhanced hydrogen evolution reaction performance

Abstract

Molybdenum disulfide (MoS₂), as one of the important two-dimensional (2D) transition metal dichalcogenides (TMDs), has shown huge potential for catalytic applications. However, both poor conductivity and insufficient active edge sites are the main obstacles limiting MoS₂ as a highly efficient electrocatalyst. In this study, a great number of edge-oriented 2D-MoS₂ nanosheets were synthesized on the surface of nickel/carbon (Ni/C) core–shell spheres. The edge-oriented MoS₂ nanosheets not only increase the number of exposed active edges, but also promote the charge transfer between active edges and Ni/C spheres. The electrochemical results show that nickel/carbon/MoS₂ (Ni/C/MoS₂) nanospheres deliver the highest activity with a Tafel slope as small as 55.5 mV per decade and an overpotential as small as 275 mV at a current density of 10 mA cm⁻². Furthermore, this Ni/C/MoS₂ core–shell architecture shows good stability and durability by the proof of 2000 cycles of cyclic voltammetry followed by a 9000 s i–t curve test. The method provides an opportunity to further improve the electrochemical catalysis of MoS₂ to produce hydrogen for energy storage.