Rose‐like Nanocomposite of Fe‐Ni Phosphides/Iron Oxide as Efficient Catalyst for Oxygen Evolution Reaction

In order to accelerate the reaction rate of water splitting, it is of immense importance to develop low‐cost, stable and efficient catalysts. In this study, the facile synthesis of a novel rose‐like nanocomposite catalyst (Ni₂P/Fe₂P/Fe₃O₄) is reported. The synthesis process includes a solvothermal step and a phosphatization step to combine iron oxides and iron‐nickel phosphides. Ni₂P/Fe₂P/Fe₃O₄ performs well in catalyzing oxygen evolution reaction, with a very low overpotential of 365 mV to reach 10 mA cm^?2 current density. The Tafel slope is as low as 59 mV dec^?1. Ni₂P/Fe₂P/Fe₃O₄ has a large double‐layer capacitance that contributes to a high electrochemically active area. Moreover, this catalyst is very stable for long‐term use. Therefore, the Ni₂P/Fe₂P/Fe₃O₄ catalyst has a high potential for use in oxygen evolution reactions.