Selenide-based 3D folded polymetallic nanosheets for a highly efficient oxygen evolution reaction.

Electrochemical water splitting, which is considered to be one of the fruitful strategies to achieve efficient and pollution-free hydrogen production, has been deemed as a key technology to achieve renewable energy conversion. Oxygen evolution reaction (OER) is a decisive step in water splitting. Slow kinetics seriously limits the effective utilization of energy thus it is extremely urgent to develop electrocatalysts that can effectively reduce the reaction energy barrier thus accelerate OER kinetics. Here, Mn-CoSe/NiSe/NF nanosheets with 3D folded structure was assembled on Ni foam by electrodeposition and vapor-deposition method. Mn-CoSe/NiSe/NF can achieve a current density of 10 mA cm with only 175 mV overpotential in an alkaline environment of 1 M KOH, which is much lower than other reported catalysts. In addition, catalyst Mn-CoSe/NiSe/NF also performed well in long-term stability tests. Through the synergy of polymetallic, the improvement of catalyst surface energy together with the tuning of electronic structure and the optimization of conductivity can be realized. This work may provide a feasible strategy for the design of efficient selenide-based oxygen evolution reaction catalysts.