Superacid-promoted synthesis of highly porous hypercrosslinked polycarbazoles for efficient CO₂ capture

A superacid-promoted "knitting" strategy has been developed for the generation of a novel family of hypercrosslinked nanoporous polycarbazoles for efficient CO₂ capture. Using trifluoromethanesulfonic acid, a Brønsted superacid, we demonstrate the facile and rapid synthesis of highly porous polycarbazoles with BET surface areas as high as 1688 m² g^-1, and capable of adsorbing 3.5 mmol g^-1 of CO₂ at 298 K and 1 bar. This impressive result bestows the material with the highest CO₂ uptake capacity for all nanoporous carbazolic polymers and ranks among the best by known porous organic polymers under this condition. This innovative approach affords a metal-free alternative to Friedel-Crafts alkylation, and may open up new possibilities for the rational design and synthesis of new hypercrosslinked nanoporous organic networks for carbon capture.