Optimizing CoFe₂O₄ coatings on nickel foam via Aerosol-Assisted CVD for superior electrochemical oxygen evolution Catalysis

The slow pace of the oxygen evolution reaction (OER) presents a major challenge for producing renewable hydrogen energy via electrocatalytic water splitting. To overcome this issue, it is essential to develop high-performing, non-precious metal-based electrocatalysts that improve OER efficiency and advance water electrolysis technology. This study investigates the OER activity of CoFe₂O₄ thin-film electrocatalysts deposited on nickel foam (NF) using an aerosol-assisted chemical vapor deposition method. The catalyst coatings, CoFe₂O₄@NF, were prepared for 30, 60, and 120 min to optimize mass loading, surface morphology, and catalytic active sites, enhancing OER performance in 1 M KOH. The 30-minute catalyst demonstrated an impressive current density of 1 A cm^–2 at a relatively low potential of 1.62 V (vs. RHE), attributed to the enhanced electrical conductivity provided by the uniform nanospherical CoFe₂O₄ layer supported on the NF scaffold, as evidenced by a low Tafel slope of 50.2 mV dec^–1. Additionally, the strong interaction of the catalyst layer with NF ensures excellent long-term stability, with the OER performance maintained for up to 24 h. These findings indicate that the CoFe₂O₄@NF catalysts developed in this study offer a promising, cost-effective alternative to noble metal catalysts for generating affordable and clean energy in water-splitting devices.