Rhombohedral Fe2O3/LaCoO3 nanomaterials as high-performance electrocatalysts for OER: Synthesis and electrochemical performance

Abstract

The development of stable, non-noble, and sustainable nanomaterials offers a viable pathway for enhancing water electrolysis operations, especially in facilitating efficient Oxygen Evolution Reaction (OER). In this study, we have prepared a rhombohedral composite nanomaterial (Fe2O3/LaCoO3) for the OER by co-precipitation method. Samples were thoroughly analyzed using multiple techniques to ensure comprehensive characterization, including X-Ray Diffraction (XRD) for crystallographic structure determination, Scanning Electron Microscopy (SEM) for surface morphology observation, Energy Dispersive X-ray Spectroscopy (EDX) for elemental composition analysis, mapping analysis to visualize spatial distribution of elements, and Fourier Transform Infrared Spectroscopy (FTIR) for identifying functional groups and chemical bonds. Prepared electrocatalyst reveals robust OER performance with an overpotential of 311 mV to achieve the 10 mAcm−2 current density in alkaline media. Significantly, this catalyst offers a low Tafel slope of 76 mV dec‑1 and a charge transfer resistance of 532 Ω with excellent Linear Sweep Voltammetry (LSV) cycling stability. The improved electrocatalytic performance results from the synergistic interaction among La, CoO3, and Fe2O3, which typically enhances the overpotential, charge-mass transport, and stability. This strategy offers a viable pathway for synthesizing and optimizing nanomaterials for advanced electrochemistry. © 2025 Elsevier B.V.