One pot fabrication of FeNi-BTC MOFs as effective electrocatalysts for oxygen evolution reaction

In context of the continuing energy crisis and the rapid depletion of fossil fuel sources, electrochemical water splitting has received substantial attention as a potential and sustainable route to hydrogen generation, providing a realistic path to a clean energy future. Electrochemical water splitting consists of two half-reactions: the oxygen evolution reaction (OER) at the anode and the hydrogen evolution reaction (HER) at the cathode. Among these, the OER remains a critical bottleneck due to its sluggish electron transfer kinetics, which significantly hinders the efficiency of water electrolysis. Consequently, the development of robust and cost-effective OER catalysts with low overpotentials is of paramount importance. In this study, bimetallic metal–organic frameworks (MOFs) with varying molar ratios of Fe and Ni (1:0, 1:1, 1:3, and 0:1) were synthesized via a solvothermal method and systematically evaluated for their electrochemical performance. Among the synthesized catalysts, the FeNi MOF with a 1:3 M ratio (FeNi 1:3) exhibited the good OER activity, with an onset potential of 1.44 V vs. RHE and necessitating just 232 mV to attain a current density of 10 mA cm⁻². Furthermore, it showed a low Tafel slope of 30.2 mV dec⁻¹, indicating favorable reaction kinetics and excellent potential for electrochemical applications. The catalyst exhibited high electrochemical active surface area (176.25 cm²) and turn over frequency of 2.80 s⁻¹at 1.77 V, which is attributed to the abundance of electroactive sites, little charge transfer impedance at the electrode-electrolyte interface, distinctive and uniform rock-like shape, and the synergistic interactions of iron and nickel in a 1:3 ratio. The electrocatalyst also demonstrated high efficiency, distinct morphological characteristics, and exceptional performance in water oxidation, highlighting its potential to advance electrocatalysis and contribute to the development of efficient and reliable and clean energy conversion technologies.