Pyridinic N–B Pair-Doped Carbon Microspheres with Refined Hierarchical Architectures for Rechargeable Zinc-Air Batteries

Refined architectures are of vital importance in determining the electrocatalytic activity of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, pyridinic N–B pair doped carbon microspheres (NB-CMS) with hierarchical micropore-mesopore structure are prepared via a SiO2 hard template assisted CO2 activation strategy. The pyridinic N–B pair accounts for ≈ 59.9% of all N species in NB-CMS, accelerating the ORR process with onset potential (0.986 V) and half-wave potential (0.879 V). Meanwhile, the NB-CMS also exhibits high OER performance with overpotential of 191 mV at 10 mA cm−2. The assembled Zinc-air battery exhibits maximum power density of 83 mW cm−2 and long-term charging and discharging stability over 82 h. Density functional theory (DFT) simulations reveal that the pyridinic N–B pair exhibits the highest electrocatalytic performance in dual-functional catalysis, owing to the highest charge density and readily accepts electrons from *OOH adsorbate of N active site neighboring B.