Spinel oxide CoFe₂O₄ grown on Ni foam as an efficient electrocatalyst for oxygen evolution reaction

The effect of the oxygen evolution reaction (OER) is important in water splitting. In this work, we develop sphere-like morphology spinel oxide CoFe₂O₄/NF by hydrothermal reaction and calcination, and the diameter of the spheres is about 111.1 nm. The CoFe₂O₄/NF catalyst exhibits excellent electrocatalytic performance with an overpotential of 273 mV at a current density of 10 mA cm⁻² and a Tafel slope of 78 mV dec⁻¹. The cycling stability of CoFe₂O₄/NF is remarkable, and it only increased by 5 mV at a current density of 100 mA cm⁻² after 3000 cycles. Therefore, this simple method to prepare CoFe₂O₄/NF can enhance the OER properties of electrocatalysts, which makes CoFe₂O₄/NF a promising material to replace noble metal-based catalysts for the oxygen evolution reaction.