Nitrogen-doped porous carbon nanosheets were synthesized viaan activation- or post-treatment-free approach, which delivered high CO 2and dye adsorption capacities.
Poly(ionic liquid) has recently served as an important precursor for nitrogen-doped functional porous carbons. It was applied here in a facile one-pot approach to synthesize nitrogen-doped porous carbon nanosheets (NPCNSs) using C 3N 4nanosheets as sacrificial templates. C 3N 4nanosheets are found to improve the carbonization yield and nitrogen content of NPCNSs and additionally facilitate the formation of a unique pore structure. Without post-treatments or activation steps, the as-synthesized NPCNS readily reaches a specific surface area above 1100 m 2g −1with hierarchical micro-/meso-/macropore structures while keeping a high nitrogen content (17.4 wt%). More significantly, the NPCNS is able to deliver not only a high CO 2adsorption capacity with outstanding reversibility, but also an unprecedented capacity in methylene blue uptake by 962.1 mg g −1, which is among the few highest ever reported for wastewater, with excellent reusability.