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

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 IrO2/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. Graphical abstract: [Figure not available: see fulltext.]