Defect engineering and atomic doping of porous Co-NiP nanosheet arrays for boosting electrocatalytic oxygen evolution.

Electrochemical hydrogen production by splitting water is mainly limited to the oxygen evolution reaction (OER), which requires high energy consumption. The design of an efficient and stable electrochemical catalyst is the key to solving this problem. Here, a three-dimensional porous Co-doped NiP nanosheet (Co-NiP/NF-corr) was synthesized by simple hydrothermal, acid leaching and phosphating processes successively. Excitingly, the current density of Co-NiP-corr in 1 M KOH solution can reach 50 mA cm with only 267 mV overpotential. Moreover, the Tafel slope is very small, only 64 mV dec. In addition, the stability test shows that it can work stably at 50 mA cm current density for at least 48 h.