A dual-template synergistic assembly strategy towards the synthesis of extra-small nitrogen-doped mesoporous carbon nanospheres with large pores

Functional mesoporous carbon nanomaterials with large pores and small particle sizes have broad accessibility, but remain challenging to achieve. This study proposed a dual-template synergistic assembly strategy to facilely synthesize extra-small nitrogen-doped mesoporous carbon nanospheres with large pores in a low-cost manner. Directed by the synergistic effect of the combination of surfactants, sodium oleate (anionic surfactant) and triblock copolymer-P123 (nonionic surfactant) were selected as templates to construct nanomicelles (nanoemulsions), which were co-assembled with melamine-based oligomers to form composite nanomicelles, thus obtaining nitrogen-doped mesoporous polymer nanospheres (NMePS) and then nitrogen-doped mesoporous carbon nanospheres (NMeCS). Based on Schiff base chemistry, the melamine-based oligomers with self-assembly capability were synthesized as precursors, which is different from the conventional synthetic route of melamine-formaldehyde resin. The key parameters involved in the route were investigated comprehensively and correlated with the characterization results. Furthermore, the 50 nm-scale particle size and the large mesoporous size of 5.5 nm of NMeCS can facilitate effective mass transport, coupled with their high nitrogen content (15.7 wt%), contributing to their excellent performance in lithium-ion batteries.