Facile Sol-Gel Synthesis of Graphene-Supported FeNi Nanocatalysts for Enhanced Oxygen Evolution Reaction

The challenge of utilizing green energy sources remains relevant nowadays, especially in developing new catalysts for hydrogen production through complete water decomposition. For this purpose, an electrocatalyst based on an Fe-Ni alloy supported by graphene was synthesized. The catalyst was prepared by using the sol-gel technique. Physicochemical characterization showed that the main crystalline phase was the FeNi alloy with an equimolar ratio. EDS showed that the elements were well distributed on the graphene matrix. Analyzing the structural properties of the catalysts revealed that the GFeNi 1:1.0 catalyst, which has the smallest average crystalline size and lowest lattice strain, exhibited superior catalytic activity due to its high density of exposed active sites. This promotes excellent mass and charge transport during oxygen evolution reaction kinetics. Consequently, the catalysts demonstrated an overpotential of 0.268 V vs RHE at 10 mA/cm² and maintained good stability in an alkaline 1 M KOH medium. The GFeNi 1:1.0 electrocatalyst showed electrochemical efficiency comparable to that of recently reported catalysts in the literature. These findings advance our understanding of ferromagnetic alloy-based materials for electrolysis applications and other electrochemical devices and highlight the potential of graphene-supported systems synthesized by sol-gel routes as cost-effective alternatives to noble metals.