MoS2 nanosheets decorated MoO2 on carbon electrode with electron-abundant reinforcement effect for boosting electrocatalytic hydrogen production

Abstract

Advancing electrocatalytic hydrogen evolution technologies critically depends on the development of inexpensive, high-performance electrocatalysts. Although molybdenum dioxide (MoO₂) and molybdenum disulfide (MoS₂) are regarded as promising non-precious metal electrocatalysts, their limited catalytic activity and low electrical conductivity hinder their broader application in electrocatalytic water splitting. In this work, a high-performance electrode, MoS₂-decorated MoO₂ grown on carbonized wood (MoS₂-MoO₂/CW), was fabricated through a combined hydrothermal and chemical vapor phase deposition (CVD) strategy. The synergistic formation of the heterostructure between MoS₂ and MoO₂ endows the electrode with superior performance compared to individual catalysts, thereby significantly accelerating the hydrogen evolution efficiency. Specifically, XPS analysis reveals that the coupling of MoS₂ and MoO₂ facilitates rapid electron transfer on the electrode surface. This not only accelerates the escape rate of H₂ but also enhances the catalytic activity for the hydrogen evolution reaction (HER). As a result, the well-designed electrode exhibies a low overpotential (106 mV) to drive 10 mA cm⁻², high double-layer capacitance, and excellent long-term stability of 100 h at a constant current density. The results offer useful guidelines for the development and fabrication of transition metal-based composite HER electrocatalysts.