Advances in the Synthesis of Covalent Triazine Frameworks

Covalent triazine frameworks (CTFs) are a class of organic polymer materials constructed by aromatic 1,3,5-triazine rings with planar π-conjugation properties. CTFs are highly stable and porous with N atoms in the frameworks, possessing semiconductive properties; thus they are widely used in gas adsorption and separation as well as catalysis. The properties of CTFs strongly depend on the type of monomers and the synthesis process. Synthesis methods including ionothermal polymerization, amino-aldehyde synthesis, trifluoromethanesulfonic acid catalyzed synthesis, and aldehyde-amidine condensation have been intensively studied in recent years. In this review, we discuss the recent advances and future developments of CTFs synthesis.