Tailoring Ni-Fe-Se film on Ni foam via electrodeposition optimization for efficient oxygen evolution reaction

The development of efficient non-precious metal electrocatalysts is essential for oxygen evolution reaction (OER) for water splitting. Among them, amorphous bimetallic NiFe-based compounds are recognized as one of the excellent candidates for efficient OER. Herein, the Ni-Fe-Se film is rationally designed via facile one-step electrodeposition with tailored active sites and thicknesses. Accordingly, the optimized sample, with an increased Fe-incorporation level and a thickness of ∼50 nm, shows a low overpotential of ∼290 mV at a current density of 40 mA cm −2 and long-term durability in 1 M KOH solution, representing its overall excellent OER performance. Furthermore, operando Raman and ex-situ XPS are used to identify the active sites for OER. This work provides some new insights into exploring earth-abundant free-standing catalysts for OER toward overall water-splitting applications.