Dynamic Investigations on CoFe₂O₄@Co₃O₄ Nano-composite as an Enhanced Electrocatalyst for Oxygen Evolution Reaction

The oxygen evolution reaction (OER) holds pivotal importance in sustainable energy conversion, as it forms the critical half-reaction in various electrochemical processes, including water splitting for hydrogen production and rechargeable metal-air batteries. Here, a CoFe₂O₄@Co₃O₄ nano-composite was synthesized using a facile hydrothermal process and deposited onto the surface of nickel foam through electrophoresis. Characterization using XRD, Raman spectroscopy, and XPS confirmed the successful synthesis of the composite, exhibiting characteristic peaks of both Co₃O₄ and CoFe₂O₄. The nano-composite exhibited a more amorphous phase than pure oxides, benefiting electrocatalytic activity. Scanning and transmission electron microscopy highlighted the composite’s morphological characteristics, showcasing a Co₃O₄ island distribution on the CoFe₂O₄ surface. Electrochemical evaluations revealed the superior oxygen evolution reaction (OER) performance of CoFe₂O₄@Co₃O₄, with low overpotentials, faster kinetics, and enhanced stability compared to pure oxides and the benchmark RuO₂ catalyst. A comprehensive analysis was carried out to investigate the dynamic behavior during electrocatalytic oxygen evolution reaction. This study unveils the intricate charge and electron transfer mechanisms between cobalt and iron atoms, providing insights into their collaborative role throughout the OER process.