▎ 摘　　要

The design of high efficiency, low-cost, and long-durability bifunctional electrocatalysts for the oxygen reduction/evolution reactions (ORR/OER) is crucial to some critical energy conversion and storage systems including fuel cells and water splitting. Herein, we developed a facile strategy to fabricate a CoNx/NiFeOx/nitrogen-doped reduced graphene oxide (N-RGO) nanocomposite derived from ternary CoNiFe-layered double hydroxides (LDHs)/polypyrrole (PPy)/RGO precursor for both ORR and OER. Based on the synergistic effect among different components, the resulting CoNx/NiFeOx/N-RGO nanocomposite exhibits not only superior ORR activities (a half-wave potential (E-1/2) of 0.78 V vs. RHE and a J(1600 rpm) of - 4.80 mA cm(-2) at 0.5 V vs. RHE) but also moderate OER activities (an overpotential eta(10 mA cm-2) of 372 mV) in alkaline media. The overall oxygen electrode performance of CoNx/NiFeOx/N-RGO demonstrates the smallest Delta E (E-OER,E- 10 mA cm-2-E-ORR,E- - 3 mA cm-2) value of 0.82 V compared with the benchmark (commercial 20 wt% Pt/C and RuO2/C). Furthermore, CoNx/NiFeOx/N-RGO shows good durability in ORR and OER, making it promising applications for oxygen electrocatalysis. Graphical abstract