Multicomponent Co₉S₈@MoS₂ nanohybrids as a novel trifunctional electrocatalyst for efficient methanol...

In view of the importance of multifunctional catalysts that can drive different electrocatalytic reactions in the same electrolyte solution, we designed and prepared a series of multicomponent nanohybrids composed of Co₉S₈ and MoS₂ derived from cobalt-doped polyoxometalate (Co-POMs) by one-pot calcination method. The obtained Co₉S₈@MoS₂ nanohybrids were composed of Co₉S₈, MoS₂, Co-Mo-S phases and assembled nanosheets, and therefore were explored as trifunctional electrocatalysts for hydrogen evolution reaction, oxygen evolution reaction, and methanol oxidation reaction (MOR) in an alkaline medium. The nanostructure and chemical components of the series of Co₉S₈@MoS₂ nanohybrids can be modulated by changing the mole ratios of H₅Mo₁₂O₄₁P to Co(NO₃)₂ precursor. Compared with the sole component and other reported Co₉S₈@MoS₂ nanohybrids, the Co₉S₈@MoS₂ nanohybrid prepared from the 1:1 ratio of PMo₁₂ and Co(NO₃)₂ exhibited superior MOR catalysis efficiency (121.4 mA cm^-2) and an extremely low overpotential (1.49 V) for overall water splitting at a current density of 10 mA cm^-2 owning to the effective synergism among Co₉S₈, MoS₂, and Co-Mo-S phase. Overall, this study provides a feasible approach to developing efficient and stable trifunctional bimetal electrocatalysts for clean-energy applications.