Sepaktakraw‐like catalyst Mn‐doped CoP enabling ultrastable electrocatalytic oxygen evolution at 100 mA·cm ⁻² in alkali media

Abstract

Abstract Seeking highly active, stable and low‐cost electrocatalysts used as both cathode and anode in overall water splitting is very crucial for the sustainable utilization of resources. Herein, a highly efficient and long‐term stable oxygen evolution reaction (OER) electrocatalyst Mn‐doped CoP on foam Ni (MnCoP/NF) is synthesized by the one‐step electrodeposition method. Owing to the synergetic effect among the Sepaktakraw‐like morphology, the doped Mn element and the binder‐free synthesis method, MnCoP/NF displays superior electrocatalytic activity and electrochemical stability toward OER. MnCoP/NF only requires an overpotential of 266 mV to deliver the current density of 10 mA·cm −2 , demonstrating an excellent electrocatalytic activity even better than that of commercial catalysts of IrO 2 /NF. And the retention rate of potential can still be maintained at 99.57% after the durability test as long as 240 h, indicating the prominent electrochemical stability of MnCoP/NF. Simultaneously, MnCoP/NF could be directly used as both cathode and anode in the two‐electrode system for overall water splitting, exhibiting a low potential of 1.97 V for reaching 100 mA·cm −2 . Impressive long‐term stability of MnCoP/NF is also observed by limited activity decay after 240‐h durability tests at 10 and 100 mA·cm −2 . Thus, this study illustrates a feasible approach to the rational design of highly active and stable electrocatalyst and also provides valuable insights on the improved electrocatalytic performance of water splitting by Mn doping.