Magnetically Enhanced Electrodes for Oxygen Evolution Reaction Using Ruthenium-Iron Oxide Nanocomposites

The sustainable production of clean, easy-to-store, and carbon-free fuels capable of meeting the needs of future generations is one of the most significant scientific challenges of the 21st century. Among the emerging strategies, the development of efficient electrocatalysts for the water-splitting reaction has attracted considerable attention. The absence of pollutant emissions during energy production underscores the potential of oxygen and hydrogen evolution reactions (OER and HER) as promising solutions to address growing global energy demands. Noble metals, such as ruthenium, have demonstrated superior performance in this application compared to transition metals, such as iron, cobalt, and nickel. While noble metals are scarce and expensive, their superior intrinsic activity often translates to enhanced catalytic performance per unit mass, improving the cost-benefit ratio when optimized amounts are employed. In this study, we investigated the effectiveness of iron oxide doped with ruthenium oxide for the OER. A hexanuclear complex composed of ruthenium and iron was synthesized and subsequently anchored onto iron oxide nanoparticles through Prussian blue-like (FeII-CN-M) interactions. The composite was calcined to fully oxidize the organic structure, yielding a material composed entirely of metal oxides. Using a 3 h heat treatment, the resulting catalyst achieved a favorable overpotential for the OER. Specifically, we observed an overpotential of 280 mV at 1 mA and favorable kinetics with a Tafel slope of 72 mV dec-1. The catalytic response was further enhanced by employing a magnetic field to craft the electrode, suggesting that this approach can optimize the performance of ruthenium-based catalysts. Ongoing efforts are focused on improving catalytic efficiency while minimizing material usage, addressing both performance and economic considerations.