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 (Ni₂ P/Fe₂ P/Fe₃ O₄ ) is reported. The synthesis process includes a solvothermal step and a phosphatization step to combine iron oxides and iron-nickel phosphides. Ni₂ P/Fe₂ P/Fe₃ O₄ 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 . Ni₂ P/Fe₂ P/Fe₃ O₄ 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 Ni₂ P/Fe₂ P/Fe₃ O₄ catalyst has a high potential for use in oxygen evolution reactions.