Interface Modulation of MoS₂/Metal Oxide Heterostructures for Efficient Hydrogen Evolution Electrocatalysis

Developing efficient earth-abundant MoS₂ based hydrogen evolution reaction (HER) electrocatalysts is important but challenging due to the sluggish kinetics in alkaline media. Herein, a strategy to fabricate a high-performance MoS₂ based HER electrocatalyst by modulating interface electronic structure via metal oxides is developed. All the heterostructure catalysts present significant improvement of HER electrocatalytic activities, demonstrating a positive role of metal oxides decoration in promoting the rate-limited water dissociation step for the HER mechanism in alkaline media. The as-obtained MoS₂/Ni₂O₃H catalyst exhibits a low overpotential of 84 mV at 10 mA cm⁻² and small charge-transfer resistance of 1.5 Ω in 1 m KOH solution. The current density (217 mA cm⁻²) at the overpotential of 200 mV is about 2 and 24 times higher than that of commercial Pt/C and bare MoS₂, respectively. Additionally, these MoS₂/metal oxides heterostructure catalysts show outstanding long-term stability under a harsh chronopotentiometry test. Theoretical calculations reveal the varied sensitivity of 3d-band in different transition oxides, in which Ni-3d of Ni₂O₃H is evidently activated to achieve fast electron transfer for HER as the electron-depletion center. Both electronic properties and energetic reaction trends confirm the high electroactivity of MoS₂/Ni₂O₃H in the adsorption and dissociation of H₂O for highly efficient HER in alkaline media.