Interface modifications for RuO2-decorated MoS2 nanosheets as excellent electrocatalysts for alkaline hydrogen evolution reactions

Abstract

The development of earth-rich, low-cost, and high-efficiency electrocatalysts toward alkaline hydrogen evolution reactions (HERs) in the water spitting process is extremely desirable yet a huge challenge. In this work, we report the synthesis of novel RuO₂/MoS₂ electrocatalysts with good conductivity and abundant active sites for efficient HER by uniformly dispersing RuO₂ nanoparticles on MoS₂ nanosheets. Benefitting from the intense electronic coupling effect endowed with interface modifications, the as-prepared RuO₂/MoS₂ electrocatalysts exhibited superior performance for HER in 1 M KOH with a very low overpotential of 36 mV at 10 mA cm⁻² and a small Tafel slope value of 34.8 mV dec⁻¹. Moreover, the introduction of RuO₂ nanoparticles improved the durability of the RuO₂/MoS₂ electrocatalysts with negligible variation in a 20 h operation. More importantly, the density functional theory (DFT) calculations further revealed the mechanism of strong electronic interaction between RuO₂ nanoparticles and MoS₂ nanosheets, which contributes to accelerating the H₂O dissociation kinetics and optimizing H adsorption Gibbs free energy. This work may provide a deeper understanding for designing efficient HER catalysts through interface modification strategies.