| Affiliation: | 1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 P. R. China
College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 P. R. China;2. Institute of Industrial Catalysis, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, 310032 P. R. China;3. Chemistry and Chemical Engineering of Guangdong Laboratory, Shantou, 515063 P. R. China;4. State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 P. R. China;5. College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 P. R. China |
| 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. |
