Hexagonal CoFe2O4/β-Ni(OH)2 heterojunction composite as an advanced electrocatalyst for the oxygen evolution reaction

Transition metal-based heterostructure materials are considered as promising alternatives to state-of-the-art noble metal-based catalysts toward the oxygen evolution reaction (OER). Herein, for the first time, a simple interface engineering strategy is presented to synthesize efficient electrocatalysts based on a novel CoFe2O4/β-Ni(OH)2 heterogeneous structure for the electrochemical OER. Remarkably, the optimized CoFe2O4/β-Ni(OH)2 electrocatalyst, benefiting from its hierarchical hexagonal heterostructure with strong electronic interaction, enhanced intrinsic activity, and electrochemically active sites, exhibits outstanding OER electrocatalytic performance with a low overpotential of 278 mV to reach a current density of 10 mA cm−2, a small Tafel slope of 67 mV dec−1, and long-standing durability for 30 h. Its exceptional OER performance makes the CoFe2O4/β-Ni(OH)2 heterostructure a prospective candidate for water oxidation in alkaline solution. The proposed interface engineering provides new insights into the fabrication of high-performance electrocatalysts for energy-related applications.