Metallic cobalt encapsulated in N-doped carbon nanowires: a highly active bifunctional catalyst for oxygen reduction and evolution

N-doped carbon nanowires encapsulated with cobalt nanoparticles are designed and fabricated through solvothermal and pyrolysis procedures by using cobalt chloride and nitrilotriacetic acid as the precursors. The catalyst (C-NTACo-500) demonstrated great potential as highly active bifunctional catalyst for oxygen reduction and oxygen evolution reactions (ORR and OER), with a half wave potential (E1/2) of 0.84 V (vs. RHE) for ORR, and a small overpotential of 0.28 V for OER. Notably, it could provide zinc air batteries (ZAB) a maximum power density of 203.4 mW cm−2, and a high specific capacity of 822.4 mAh gZn−1, as well as excellent charge–discharge stability.