CoN x /NiFeO x /nitrogen-doping reduced graphene oxide nanocomposite derived from layered double hydroxide precursor as an efficient bifunctional electrocatalyst for oxygen electrocatalytic reactions

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 (E1/2) of 0.78 V vs. RHE and a J1600 rpm of − 4.80 mA cm−2 at 0.5 V vs. RHE) but also moderate OER activities (an overpotential η10 mA cm−2 of 372 mV) in alkaline media. The overall oxygen electrode performance of CoNx/NiFeOx/N-RGO demonstrates the smallest ΔE (EOER, 10 mA cm−2-EORR, − 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.