Phosphoric acid-assisted synthesis of FeCo nanoalloys in N-doped carbon fibers toward high-efficiency oxygen evolution reaction

The oxygen evolution reaction (OER) is a core half-reaction in clean energy technologies like water splitting, and the development of high-efficiency OER catalysts is critical for overcoming the energy conversion efficiency bottleneck. The development of efficient OER catalysts based on metal-embedded porous carbon nanofibers (CNFs) is often hampered by complex synthesis procedures. This study presents a phosphoric acid-mediated synthesis strategy for fabricating FeCo bimetallic nanoalloys anchored on nitrogen-doped porous carbon nanofibers (FeCo@N-PCNFs). By integrating phosphoric acid with polyvinyl alcohol (PVA), a stabilized carbon framework is formed, enabling homogeneous dispersion of FeCo nanoparticles. Hierarchical porosity is simultaneously generated through PTFE decomposition during pyrolysis. The optimized FeCo@N-PCNFs demonstrate superior OER performance in 1 M KOH, requiring an overpotential of 273 mV to reach 10 mA cm −2 , outperforming commercial RuO 2 (320 mV). The catalyst maintains 91.4% of its initial current over 32 h, with enhanced charge transfer kinetics (R ct  = 0.77 Ω). This method simplifies the synthesis of porous carbon-based electrocatalysts while achieving high activity and durability.