In Situ Construction of Cobalt-Doped High-Dispersive Heazlewoodite for Efficient Oxygen Evolution

Water electrolysis to produce hydrogen has been considered the most potential strategy in the renewable energy area but is restricted by the sluggish kinetics at the anode oxygen evolution. In this work, we design and construct cobalt-doped heazlewoodite (Co–Ni3S2) catalysts via a simple one-step in situ sulfurization strategy. The Co–Ni3S2 spheres are fixed on a nickel foam (NF) substrate with a high-dispersive property. The replacement reaction between Co2+ and the NF substrate has taken place with the assistance of a sulfur resource, resulting in cobalt doping in the Ni3S2 spheres. In terms of the oxygen evolution reaction (OER) activity and reaction kinetics of the catalysts, Co–Ni3S2 plays the highest OER performance, which is mainly ascribed by the Co dopants in tuning the morphology and intrinsic properties of the catalyst. In combination of the superior electrochemical stability, Co–Ni3S2 would be a potential candidate in practical industrial water electrolysis.