Alloy Foam-Derived Ni0.86Fe2.14O4 Hexagonal Plates as an Efficient Electrochemical Catalyst for the Oxygen Evolution Reaction

Synthesis of binary electrocatalysts from substrates is ideal for further integration of water-splitting electrodes. The seamless growth of an electrocatalyst directly from an alloy substrate would provide excellent mechanical behavior and lower interface resistance. Herein, a three-dimensional (3D) intertwined Ni0.86Fe2.14O4 hexagonal plate electrocatalyst as the active site for the oxygen evolution reaction (OER) was successfully prepared by seamless growth and direct synthesis on Ni-Fe foam (NFF) via a hydrothermal route. Ni0.86Fe2.14O4/NFF exhibited excellent OER electrochemical properties, achieving a low overpotential of 286 mV to reach a current density of 200 mA cm(-2) and prominent electrochemical durability. The synergistic effect between Ni and Fe in Ni0.86Fe2.14O4 and the seamless connection between Ni0.86Fe2.14O4 and the substrate make main contribution to excellent OER activity for the electrode system. This synthesis strategy provides a route for the synthesis of binary metal-oxide electrocatalysts from alloys, which can be extended to other binary electrocatalysts.