Fe doped Ni5P4 nanosheet arrays with rich P vacancies via phase transformation for efficient overall water splitting
Proper vacancy engineering is considered as a promising strategy to improve the intrinsic activity, but it is challenging to construct rich vacancies by a simply strategy without special equipment. Herein, Fe doped Ni5P4 nanosheet arrays with rich P vacancies are developed via a facile phase transformation strategy. Based on systematical investigations, we demonstrate that the optimized surface electronic structure, more abundant active sites and improved charge transport capability can be effectively achieved by vacancy engineering. Consequently, Fe doped Ni5P4 with rich vacancies show remarkable catalytic performances with 94.5 mV for hydrogen evolution reaction (HER) and 217.3 mV for oxygen evolution reaction (OER) at 10 mA cm-2 respectively, as well as good durability. When directly employed as working electrodes, as-obtained Fe doped Ni5P4 with rich vacancies can attain 10 mA cm-2 at low voltage of 1.59 V. This work highlights a feasible strategy for rationally fabricating electrocatalysts with rich vacancies via the simple phase transformation.