Brave New Frameworks: Synthesis and Structural Properties of Novel Covalent Triazine Frameworks From Commercial...

Covalent triazine frameworks (CTFs) have promising photocatalytic applications including water treatment and the conversion of CO₂. This study investigates the utilization of the commercially available precursors 1,2-dicyanobenzene (1,2-DCB) and 1,3-dicyanobenzene (1,3-DCB) to synthesise novel CTF-type materials. The structure and properties of these materials are compared with those of the benchmark photocatalyst CTF-1, which is synthesised from 1,4-dicyanobenzene (1,4-DCB). Although the materials derived from 1,2-DCB and 1,3-DCB as well as 1,4-DCB contain triazine units characteristic of CTFs, the 2D and 3D structural properties differ substantially depending on the DCB precursor. The geometry of 1,2-DCB prevents the formation of ordered porous networks, leading to materials that lack semiconducting properties, hence without potential use in photocatalysis. By contrast, materials derived from 1,3-DCB show greater similarity to CTF-1, with a proposed extended 2D network structure, a high thermal stability, and visible light absorption. However, the crystallinity and overall surface area of the 1,3-DCB-derived products are lower than values reported for CTF-1. Photocatalytic activity towards the aerobic oxidation of benzylamine is demonstrated for the catalysts derived from 1,3-DCB and compared with materials prepared from 1,4-DCB. Overall, this study demonstrates that commercially available DCBs can form triazine-containing CTF-type materials with tuneable structural and optical properties.