MnS–MnO heterogeneous nanocube@N, S‐doped carbon as a highly efficient bifunctional water splitting electrocatalyst

Abstract A stable, efficient, and economical bifunctional electrolytic catalyst would be incredibly beneficial for the development of hydrogen production by electrocatalytic water splitting. In this study, we synthesized a novel MnS–MnO heterogeneous nanocube@N, S‐doped carbon (MnS–MnO@NSC). MnS–MnO nanocubes possess rich heterogeneous interfaces and plentiful catalytic active sites to promote electrochemical reactions, while the N, S‐doped carbon shell possesses excellent conductivity and catalytic properties and protects the nanocubes. MnS–MnO@NSC exhibited excellent electrochemical properties as an effective bifunctional electrocatalyst for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in KOH solution. In the HER, the overpotential was as low as 124 mV at a current density of 10 mA·cm −2 , while in the OER, it was only 340 mV at 100 mA·cm −2 under the same conditions. In addition, a MnS–MnO@NSC||MnS–MnO@NSC electrolyzer exhibited almost comparable activity and higher steadiness than those exhibited by the state‐of‐the‐art Pt/C||RuO 2 /C system for full water splitting in KOH solution.