Interface Engineering of CoO/N-Doped Carbon Nanomaterials as a Bifunctional Electrocatalyst for Rechargeable Zinc-Air Batteries

Robust bifunctional and highly efficient electrocatalysts for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) exhibits great prospect in a zinc-air battery (ZAB). Here, we demonstrated a facile route to synthesize a bifunctional electrocatalyst with CoO nanoparticles embedded in N-doped carbon by interface engineering. The precursor which consists of ball-milled polyaniline (BM-PANI), carbon nanotubes (CNTs) and cobalt acetate tetrahydrate (Co(Ac)(2)center dot 4H(2)O) was obtained via homogeneous mixture in the presence of ethanol, and thus, satisfactory interface was formed. After calcination, the synthesized CoO/N-doped carbon composite material presents a half-wave potential of 0.818 V for ORR and an overpotential of 0.417 V at 10 mA cm(-2) for OER, which endows it a power density of 92.04 mW cm(-2) in a homemade rechargeable ZAB and a high stability outperforming commercial Pt/C. This work highlights the mixture of precursors by interface engineering, thus improving the synergistic effect between metal oxide and carbon and elevating the electrocatalytic activity.