Coral‐like nitrogen doped carbon derived from polyaniline‐silicon nitride hybrid for highly active oxygen reduction electrocatalysis

In this work, a coral‐like nitrogen‐doped carbon electrocatalyst has been prepared via self‐assembly oxidative polymerization of aniline monomers onto silicon nitride (Si3N4) nanospheres, followed by carbonization. The prepared catalyst at 900°C (denoted as NC‐900) shows excellent oxygen reduction reaction (ORR) activity by achieving an onset potential (η) of 0.90 V versus reversible hydrogen electrode (RHE) and half wave potential (E1/2) of 0.82 V versus RHE comparable to that of the commercial Pt/C (η = 0.99 V vs. RHE and E1/2 = 0.87 V vs RHE) and even outperforming many carbon‐based electrocatalysts recently reported in the literature. The catalyst NC‐900 also displays better stability and resistance toward methanol crossover effect than Pt/C in alkaline solution. The high ORR performance of NC‐900 catalyst was associated with high content of nitrogen species and hierarchical mesoporous structure that facilitate high electron and mass transport.