In Situ Construction of RuS₂-MoO₃/MoS₂ Heterostructure for Efficient Hydrogen Evolution in Alkaline Media

The investigation of an electrocatalyst that integrates both high activity and cost-effectiveness to enhance the sluggish kinetics of the hydrogen evolution reaction (HER) during water reduction constitutes a significant scientific challenge. Herein, we present an electrocatalyst that RuS₂ nanoparticles were uniformly dispersed onto MoO₃/MoS₂ nanosheets support to obtain abundant heterojunction interfaces of RuS₂-MoO₃/MoS₂ for efficient HER. It enhanced the activity of RuS₂ for alkaline HER to charged interactions between RuS₂ and MoO₃/MoS₂ with accelerating the rate of water dissociation and optimizing the reaction kinetics. RuS₂-MoO₃/MoS₂ heterostructure exhibits excellent electrocatalytic performance for alkaline HER, showing a low overpotential of only 51 mV at current density of 10 mA cm^-2 and a low Tafel slope of 46 mV dec^-1, outperforming commercial Pt/C and most previously reported alkaline HER electrocatalysts. Moreover, it also has outstanding long-term stability, capable of maintaining current densities of 10 mA cm^-2 and 100 mA cm^-2 for durations exceeding 500 hours and 100 hours under the chronoamperometric method, respectively. This research offers novel insights and clear guidance for the development of high-performance, cost-effective RuS₂ electrocatalysts.