One-step electrodeposition of composition-controllable dendritic NiFe alloy electrocatalysts for oxygen evolution reaction

The development of cost-effective, highly stable, and efficient catalysts for the oxygen evolution reaction (OER) is a crucial step for large-scale industrial application of water electrolysis. This study introduces a facile and swift one-step electrodeposition method for the in-situ formation of dendritic NiFe alloy electrocatalysts supported on a nickel mesh. By fine-tuning the current density during electrodeposition, both the morphology and the nickel-iron ratio of the NiFe alloy can be optimized to enhance its OER performance. With an optimized nickel-iron ratio, the dendritic NiFe alloy catalyst demonstrates outstanding performance, achieving a current density of 10 mA·cm−2 at an overpotential of 242 mV in 1 M KOH solution, with a smaller charge transfer resistance (Rct) of 1.033 Ω and a low Tafel slope of 56.64 mV·dec−1. Moreover, the NiFe alloy catalyst exhibits good stability, maintaining a consistent current density of 10 mA·cm−2 over 30 h period with negligible fluctuations in overpotential. Moreover, at a current density of 50 mA·cm−2, the Faradaic efficiency for O2 achieves an impressive rate of 97.70%. This work presents a facile and efficient approach for the controlled synthesis of NiFe alloy OER electrocatalysts, providing a potential catalyst for industrial-scale water electrolysis applications.