Towards Effective Utilization of Nitrogen-Containing Active Sites: Nitrogen-doped Carbon Layers Wrapped CNTs Electrocatalysts for Superior Oxygen Reduction

•Active sites rendered by the surface enriched N are more effective to catalyze ORR.•The CNT assures the rapid electron transport to N-containing catalytic active sites.•The elaborately introduced MnO2 template ensures the formation of the NC well-wrapped CNT nanocomposits.•The designed CNT@NC exhibits superior ORR performance in alkaline media.

The great challenge of designing nitrogen-doped carbon catalysts for oxygen reduction reaction (ORR) is how to reach high utilization of nitrogen-containing active sites and high electrocatalytic performance. By considering the requirements for achieving high nitrogen utilization, proper nitrogen bonding state, and sufficient electron transportation, this work developed a core–shell nanostructured CNT@NC composite with an N-containing carbon shell well-wrapped around a carbon nanotube (CNT) core based on a sacrificed template method. The easily accessible nitrogen atoms enriched on the surface, combined with the contacted CNT electron highways, render the N-containing active sites at outer shell with high ORR catalytic efficiency.

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