In situ transformation from metal-organic framework into iridium-iron hollow hexagonal rod to promote oxygen evolution reaction

Developing highly efficient and durable electrocatalysts for water oxidation in alkaline media is crucial for hydrogen production in industrialization. IrO2 is a highly promising electrocatalyst for oxygen evolution reaction (OER), but its large-scale is still limited to the sluggish OER kinetics in alkaline solution due to the multi-steps adsorption of -OH and H2O. Herein, we reported a novel in-situ generation from metal-organic framework strategy for preparing hollow hexagonal rod IrFex electrocatalysts (IrFex HHRs). Specifically, the optimized IrFe3 HHRs shows an excellent OER electrocatalytic activity, including low overpotential of 265, 295 and 307 mV at the current density of 10, 50 and 100 mA cm−2, and high stability (100 h). The experimental results revealed that the existent interfacial Fe-O-Ir bonds between Ir and MIL-88A (Fe) can promote electrons transport to improve the electrocatalyst activity. This work represents a new strategy for designing an efficiency electrocatalysts with low iridium content derived from Ir doped-bimetal MOF material.