Cobaloxime anchored MoS2 nanosheets as electrocatalysts for the hydrogen evolution reaction

Abstract

Molybdenum disulfide (MoS₂) has emerged as a promising electrocatalyst for the hydrogen evolution reaction (HER). However, the catalytic performance of pure MoS₂ is not as good as expected due to the limited active sites at the surface. Herein, cobaloxime anchored MoS₂ nanosheets (MoS₂–Co(dmgBF₂)₂) were successfully developed as electrocatalysts for the HER in acidic media. Remarkably, MoS₂–Co(dmgBF₂)₂ delivered a current density of 10 mA cm⁻² at a low overpotential of approximately 103 mV versus the reversible hydrogen electrode, which is much lower than the values of most reported MoS₂-based HER electrocatalysts. In addition, the Tafel slope and the exchange current density of MoS₂–Co(dmgBF₂)₂ were calculated to be 45 mV dec⁻¹ and 64.5 μA cm⁻², respectively. Such superior HER activity can be attributed to the abundant active sites from both the edges and the modified basal planes. We believe that this approach not only provides a new method to functionalize MoS₂ through coordination, but also offers a new approach to integrate homogeneous and heterogeneous catalysts for the HER.