Anchoring CoFe₂O₄ Nanoparticles on N-Doped Carbon Nanofibers for High-Performance Oxygen Evolution Reaction

The exploration of earth-abundant and high-efficiency electrocatalysts for the oxygen evolution reaction (OER) is of great significant for sustainable energy conversion and storage applications. Although spinel-type binary transition metal oxides (AB₂O₄, A, B = metal) represent a class of promising candidates for water oxidation catalysis, their intrinsically inferior electrical conductivity exert remarkably negative impacts on their electrochemical performances. Herein, we demonstrates a feasible electrospinning approach to concurrently synthesize CoFe₂O₄ nanoparticles homogeneously embedded in 1D N-doped carbon nanofibers (denoted as CoFe₂O₄@N-CNFs). By integrating the catalytically active CoFe₂O₄ nanoparticles with the N-doped carbon nanofibers, the as-synthesized CoFe₂O₄@N-CNF nanohybrid manifests superior OER performance with a low overpotential, a large current density, a small Tafel slope, and long-term durability in alkaline solution, outperforming the single component counterparts (pure CoFe₂O₄ and N-doped carbon nanofibers) and the commercial RuO₂ catalyst. Impressively, the overpotential of CoFe₂O₄@N-CNFs at the current density of 30.0 mA cm^-2 negatively shifts 186 mV as compared with the commercial RuO₂ catalyst and the current density of the CoFe₂O₄@N-CNFs at 1.8 V is almost 3.4 times of that on RuO₂ benchmark. The present work would open a new avenue for the exploration of cost-effective and efficient OER electrocatalysts to substitute noble metals for various renewable energy conversion/storage applications.