3D self-supporting porous NiFe2O4-Ni3P-Fe2P film with sea urchin-like structure for efficient oxygen evolution

Efficient, low-cost and stable eletrocatalysts for oxygen evolution reaction (OER) is critical in commercial largescale water electrolysis. Herein, a 3D self-supporting porous NiFe2O4-Ni3P-Fe2P film with sea urchin-like structure was fabricated by one-step electrodeposition, phase separation during the annealing, and selective oxidation thermal treatment. The multi-phase NiFe2O4-Ni3P-Fe2P film exhibited superior OER elerocatalytic activity and the long-term stability in alkaline solution. The overpotentials were 102 and 641 mV at current densities of 10 and 200 mA cm-2, respectively. The Tafel slope was 42 mV dec-1. The excellent performance could be attributed to the plentiful active sites provided porous sea urchin-like structure, the good conductivity of NiFe2O4, the synergetic effect of multiphase structure and the superior wettability. The features of NiFe2O4Ni3P-Fe2P film display promising application potential in the field of electrochemistry.