Influence of Monolayered RuO₂ Nanosheets and Co²⁺ Ion Linkers in Improving the Electrocatalytic Performance of MoS₂ Nanoflowers

Hybridization between low-dimensional nanostructures has received considerable research interest, owing to its usefulness in the exploration of energy-efficient functional materials. In the present study, an effective method to synthesize high-performance electrocatalysts was established by employing monolayered two-dimensional RuO₂ nanosheets and Co²⁺ ions as conductive additives and linker species, respectively. Intimately coupled hybrid electrocatalysts of Co–MoS₂–RuO₂ were synthesized through the self-assembly of isocharged MoS₂ nanoflowers and RuO₂ nanosheets using oppositely charged Co²⁺ linkers. Efficient interfacial charge transfer from RuO₂ nanosheets to MoS₂ nanostructures can be achieved via electrostatically driven strong electronic coupling between MoS₂/RuO₂ nanostructures promoted by Co²⁺ linkers. The co-incorporation of RuO₂ nanosheets and Co²⁺ ion linkers was found to be considerably effective for optimization of the electrocatalyst performance and electrochemical stability of MoS₂ nanoflowers for the hydrogen evolution reaction in acidic and alkaline electrolytes. The beneficial roles of RuO₂ nanosheets and Co²⁺ ions in the optimization of the electrocatalyst performance were attributable to the improvement of electrocatalysis kinetics, the expansion of the electrochemical active surface area, and the promotion of charge transport upon hybridization.