Multicomponent CoS@MoS nanohybrids as a novel trifunctional electrocatalyst for efficient methanol electrooxidation and overall water splitting.

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 CoS and MoS derived from cobalt-doped polyoxometalate (Co-POMs) by one-pot calcination method. The obtained CoS@MoS nanohybrids were composed of CoS, MoS, 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 CoS@MoS nanohybrids can be modulated by changing the mole ratios of HMoOP to Co(NO) precursor. Compared with the sole component and other reported CoS@MoS nanohybrids, the CoS@MoS nanohybrid prepared from the 1:1 ratio of PMo and Co(NO) exhibited superior MOR catalysis efficiency (121.4 mA cm) and an extremely low overpotential (1.49 V) for overall water splitting at a current density of 10 mA cm owning to the effective synergism among CoS, MoS, and Co-Mo-S phase. Overall, this study provides a feasible approach to developing efficient and stable trifunctional bimetal electrocatalysts for clean-energy applications.