MOF-Derived Porous Fe₃O₄/RuO₂-C Composite for Efficient Alkaline Overall Water Splitting

Development of highly active, durable, bifunctional electrocatalysts for overall water splitting is of great importance to enhance the use of hydrogen energy. Herein, we synthesize a porous and interfaces-rich Fe3O4/RuO2-C composite from the Metal organic frameworks (MOF) material for overall water splitting in alkaline media. The Fe3O4/RuO2-C catalyst showed superior oxygen evolution reaction (OER) with high faradic efficacy. It requires 268 mV overpotential to achieve the current density of 20 mA/cm2. The catalyst also exhibited good hydrogen evolution reaction (HER) with a current density of 10 mA/cm2 at an overpotential of 94 mV. The stability test confirmed a remarkable long-term OER and HER stability of this catalyst in alkaline media. In addition, the Fe3O4/RuO2-C catalyst was also used as cathode and anode material for overall water splitting. It showed superior activity and stability in alkaline media with 10 mA/cm2 current density at 1.595 V cell potential. The excellent electrocatalytic activity of the Fe3O4/RuO2-C catalyst can be attributed to its porous structure, synergistic interaction between the components, the presence of hetero-interfaces, high electrochemical surface area etc. This work may provide an opportunity to design a bifunctional electrocatalyst for the development of anion exchange membrane water electrolyzers (AEMWEs).