The Asymmetrical Fe‐O‐Se Bonds in Fe2O(SeO3)2 Boosting Bifunctional Oxygen Electrocatalytic Performance for Zinc‐Air Battery

Here Fe2O(SeO3)2/Fe3C@NC catalysts with high performance were fabricated for zinc‐air batteries (ZABs). The experimental results confirmed that the existence of Fe‐O‐Se bonds in Fe2O(SeO3)2 crystal phase, and the Fe‐O‐Se bonds could obviously enhance ORR and OER catalytic performance of Fe2O(SeO3)2/Fe3C@NC. Density functional theoretical calculations (DFT) confirmed that the Fe2O(SeO3)2 in Fe2O(SeO3)2/Fe3C@NC had a higher d‐band center of Fe atom and a lower p‐orbital coupling degree with its own lattice O atom than Fe2O3, which leads to Fe site of Fe2O(SeO3)2 being more likely to adsorb external oxygen intermediates. The Fe‐O‐Se bonds in Fe2O(SeO3)2 results in the modification of coordination environment of Fe atoms and optimizes the adsorption energy of Fe site for oxygen intermediates. Compared with Fe2O3/Fe3C@NC, the Fe2O(SeO3)2/Fe3C@NC showed obvious enhancements of ORR/OER catalytic activities with a half‐wave potential of 0.91 V for ORR in 0.1 M KOH electrolyte and a low overpotential of 345 mV for OER at 10 mA cm‐2 in a 1.0 M KOH electrolyte. The peak power density and specific capacity of Fe2O(SeO3)2/Fe3C@NC‐based ZABs are higher than those of Pt/C+RuO2‐ZABs. The above results demonstrate that the asymmetrical Fe‐O‐Se bonds in Fe2O(SeO3)2 plays a key role in improving the bifunctional catalytic activities of ORR/OER for ZABs.