A facile synthesis of hierarchical CoFe2O4 nanosheets for efficient oxygen evolution in neutral medium

It is of great significance to develop electrocatalysts that are abundant in Earth's crust, highly efficient, and exceptionally durable for the oxygen evolution reaction (OER), particularly in neutral media. Herein, the hierarchical CoFe2O4 nanosheets supported on iron foam (CoFe2O4/IF) are prepared by the ambient spontaneous redox reaction between iron foam and Co2+ at room temperature. The as-obtained CoFe2O4/IF electrode presents excellent electrocatalytic OER activity with an overpotential of 429 mV at 10 mA cm−2 and maintains the stability of 50 h in 1 M PBS. The outstanding electrocatalytic OER activity of CoFe2O4/IF can be credited to the decreased transfer resistance and unique structural features. In addition, the CoFe2O4/IF presented here holds promise for noble-metal-free OER electrocatalyst.