Sol-gel-engineered Co 3 O 4 –Fe 2 O 3 /reduced graphene oxide composites: interfacial effects and enhanced oxygen evolution electrocatalysis

The Co₃O₄-Fe₂O₃/reduced graphene oxide (rGO) composite was synthesized via a sol-gel technique and evaluated as an electrocatalyst for the oxygen evolution reaction (OER) in alkaline media. Its structural, morphological, and electrochemical properties were investigated using X-ray diffraction, field-emission scanning electron microscopy, and electrochemical measurements. The results confirmed the successful synthesis of the composite and its suitability for OER applications. The composite exhibited an overpotential of 200 mV at a current density of 10 mA cm⁻2 and a Tafel slope of 74 mV dec⁻1, indicating favorable OER kinetics. Furthermore, the catalyst demonstrated operational stability over 24 h, highlighting its potential for sustained electrochemical performance. The enhanced catalytic activity is attributed to the synergistic interaction between the Co₃O₄ and Fe₂O₃ phases, improved electrical conductivity provided by rGO, and increased accessibility of electrochemically active sites. These findings suggest that the Co₃O₄-Fe₂O₃/rGO composite is a promising electrocatalyst for efficient oxygen evolution in alkaline environments.