ZIF-67-derived Se-doped CoSe2 grown on carbon nanofibers as oxygen electrocatalysts for rechargeable Zn-air batteries

Exploring bifunctional electrocatalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), which combine the features of effective electrocatalytic activity, high electrical conductivity, and superior stability, remains a significant challenge for rechargeable Zn-air batteries (ZABs). Herein, we report a material, selenium (Se)-doped CoSe2 embedded in carbon nanofibers (CNFs) (denoted as Se-CoSe2/CNFs), which was synthesized as a bifunctional electrocatalyst for ZABs via electrospinning combined with in situ growth of Zeolitic Imidazolate Framework-67 strategy, followed by carbonization and a facile selenization process. The as-synthesized Se-CoSe2/CNF electrode exhibits satisfactory electrochemical performance in an alkaline environment with a low overpotential of 325 mV at 10 mA cm(-2) toward OER and a half-wave potential of 0.80 V for ORR. Remarkably, the Se-CoSe2/CNF catalyst-based ZAB shows a peak power density of 149.4 mW cm(-2) and the voltage window barely changes after 180 h of cycling at 5 mA cm(-2), which proves its great potential application for advanced bifunctional electrocatalysis in ZABs.