Achieving highly efficient overall water splitting by Mo-doped cobalt sulfide/selenide heterostructure microsphere

Rational design and construction of electrocatalysts with fascinating property and endurance are indispensable for overall water splitting. In this work, a novel sodium molybdate etching/doping treatment coupled with sulfurating/selenizing strategy to realize Mo-doped cobalt sulfide/selenide heterostructure (Mo-CoSe2/Co3S4 microsphere) is designed. The as-prepared Mo-CoSe2/Co3S4 microsphere delivers glorious electrochemical property and endurance in hydrogen evolution reaction (HER)/oxygen evolution reaction (OER) by virtue of the desirable electronic structure, unique microsphere-like morphology, and rich heterogeneous interface. As expected, the overpotential of Mo-CoSe2/Co3S4 microsphere for HER is 87 mV at 10 mA cm−2. Additionally, Mo-CoSe2/Co3S4 microsphere acquires excellent OER activity is 233 mV at 10 mA cm−2. Mo-CoSe2/Co3S4 indicates superior characteristics that can replace noble-based catalysts for electrochemical water splitting. Overall, a novel strategy is proposed to construct high-performance materials in the next-generation energy conversion devices.