FeCo-Oxalate Organic Framework as an Efficient Electrocatalyst for Oxygen Evolution Reaction

Developing nonprecious metallic electrocatalysts for water splitting is of vital importance for sustainable environment and energy technologies. As for oxygen evolution reaction (OER), FeCo-based bimetallic catalysts have been found to act as promising candidates owing to their high intrinsic activity. Herein, a novel FeCo-oxalate organic framework was grown on nickel foam (FeCo-OA@NF) under mild conditions. The optimized electrocatalyst shows good OER performance with a low overpotential of 275 mV at the current density of 100 mA cm⁻² in alkaline environment, comparable to that of commercial Ru-based catalyst. Moreover, the quantification of produced oxygen by both gas chromatography and drainage method demonstrates nearly 100 % Faradaic efficiency. Except for the contribution of Fe and Co species for the excellent OER catalytic activity, in-situ Raman spectroscopy reveals that the positive effect of oxalate coordination also makes a difference, which can possibly reduce electron transport resistance and provide more active sites. This work provides a promising approach for the preparation of alkaline oxygen evolution electrocatalysts with low-cost and high performance.