Mn-doped NiCo2S4 nanosheet array as an efficient and durable electrocatalyst for oxygen evolution reaction

The development of self-supported nanosheet materials with porous multiple active sites has enormous potential for the application of oxygen evolution reaction (OER). Herein, we reported a three-dimensional (3D) porous nanosphere Mn-NiCo2S4/NF catalyst for OER. As a result, the simple Mn doping strategy results in good electrocatalytic performance and outstanding stability. During the OER, the Mn-NiCo2S4/NF only needs a small overpotential of 220 mV (40 mV lower than pure NiCo2S4/NF) to achieve the current density of 10 mA cm−2, which is mainly due to a large number of exposed active sites and adequate pathways for mass diffusion and oxygen gas release. Moreover, Mn doping optimizes the electronic structure and thus facilitates electron transport, leading to superior electrocatalytic performance. The catalyst exhibits incredible corrosion resistance in 1 M KOH solution for 60 h or more. This work provides a valuable method to synthesize a low cost, high-efficiency, and corrosion resistant transition metal electrocatalyst for oxygen evolution using heteroatom doping strategy.