Preparation of Fe‐doped Transition Metal Phosphides using Ionic Liquid as Precursor for Efficient Oxygen Evolution Reaction

Abstract For electrocatalysts in water splitting, activity and stability is at high are pivotal current density. Thus, transition metal phosphides were prepared using ionic liquid as precursor on nickel foam, where Fe was doped and this catalyst was covered by carbon. This Fe‐CoNiP−C/NF exhibits excellent OER activity, which only needs overpotentials of 355 and 424 mV to reach the current densities of 50 and 100 mA cm −2 , respectively. Moreover, it obtains a good stability for more than 30 hours at 100 mA cm −2 . Experimental results demonstrate part of this TMPs‐based catalyst is oxidized to metal oxyhydroxide species after phosphidation, which can significantly improve the activity for OER. Also, the low Fe doping and outer carbon enhance the OER activity and stability.