The Heterointerface between Fe₁/NC and Selenides Boosts Reversible Oxygen Electrocatalysis

Abstract

The rational design and construction of efficient and inexpensive bifunctional oxygen electrocatalysts are highly desirable for the development of rechargeable Zn–air batteries (ZABs). Although single‐atom Fe sites anchored on N‐doped carbon catalysts (Fe₁/NC) ensure high oxygen reduction reaction activity, their unitary atomically dispersed active center faces difficult condition in catalyzing oxygen evolution reaction simultaneously. Herein, a composite catalyst containing heterointerface between Fe₁/NC and selenides ((Fe,Co)Se₂) is constructed. The obtained (Fe,Co)Se₂@Fe₁/NC exhibits extremely narrow potential gap of 0.616 V and remarkable stability in alkaline media, outperforming the benchmark catalysts (Pt/C+RuO₂: 0.720 V). Experimental results and density functional theory calculations reveal that heterointerface between Fe₁/NC and (Fe,Co)Se₂ accelerates the electron transfer and provides more moderate adsorption sites, which endow (Fe,Co)Se₂@Fe₁/NC with extremely high bifunctional oxygen catalytic activity. This study not only provides a superior bifunctional catalyst for ZABs, but also enriches the application of single‐atom catalysts in multifunctional energy storage and conversion devices.