Synthesis of one-dimensional vanadium-doped CoS/Co9S8 heterojunctions as bifunctional electrocatalysts for zinc-air battery

Cobalt-based electrocatalysts have been considered promising materials for the oxygen evolution reaction (OER). Herein, we now report the synthesis of vanadium-doped CoS/Co9S8 heterostructures embedded on carbon nanorods (V-CoS/Co9S8@CNR), which was realized through one-step sulfurization of Zeolitic Imidazolate Framework-67 (ZIF-67) grown on V2O5 nanorods (V2O5@ZIF-67). The results of experiment and theoretical calculation verified that because of the vanadium dopant and the coupled nanointerface that can expedite the synergistic effect of Co9S8 and CoS, the obtained V-CoS/Co9S8@CNR showed an excellent OER catalytic performance (269 [email protected] mA/cm2) and comparable ORR catalytic performance. The assembled rechargeable Zn-air batteries displayed a superior performance as well as high charging–discharging cycling stability (>200 h) with a slight increase in the voltage gap.