Oxidative atmosphere-driven formation of single-phase spinel CuRh ₂ O ₄ nanofibers for alkaline water oxidation

Cu–Rh bimetallic single-phase spinel oxide nanofibers were synthesized via electrospinning followed by post-annealing in precisely controlled oxidative environments. By systematically tuning the O 2 concentration in the He carrier gas flow during the annealing process, the optimal atmosphere was identified to produce phase-pure CuRh 2 O 4 . The as-prepared CuRh 2 O 4 nanofibers exhibited excellent electrocatalytic performance toward the oxygen evolution reaction in 1.0 M NaOH (aq), highlighting the importance of atmosphere-controlled thermal treatment for engineering high-activity spinel oxide electrocatalysts.