A Fullerene Seeded Strategy for Facile Construction of Nitrogen‐Doped Carbon Nano‐Onions as Robust Electrocatalysts

Abstract

AbstractCarbon nano‐onions (CNOs) as a novel form of carbon materials hold peculiar structural features but their electrocatalytic applications are largely discouraged by the demanding synthesis conditions (e.g., ≥1500 °C and vacuum). Using C60 fullerene molecules as the sacrificial seeds and melamine as the main feedstock, herein, a novel strategy for the facile construction of CNOs nanoparticles is presented with ultrafine sizes (≈5 nm) at relatively low temperatures (≤900 °C) and atmospheric pressure. During the calcination, in‐depth characterizations reveal that C60 can retain the melamine‐derived graphitic carbon nitride from complete sublimation at high temperatures (≥700 °C). Owing to the N removal and subsequent pentagon generation, severely deformed graphitic fragments together with the disintegrated C60 molecules merge into larger sized nanosheets with high curvature, eventually leading to the formation of N‐doped defect‐rich CNOs. Owing to the integration of multiple favorable structural features of pentagons, edges, and N dopants, the CNOs obtained at 900 °C present superior oxygen reduction half‐wave potential (0.853 VRHE) and zinc–air cathode performance to the commercial Pt/C (0.838 VRHE). Density functional theory calculation further uncovers that the carbon atoms adjacent to the N‐doped edged pentagons are turned into the ORR‐active sites with O2 protonation as the rate‐determining step.