Covalent triazine framework nanoribbons via polar Solvent-induced fragmentation for ultrafast and Solar-cleaning membrane separation

• We for the first time synthesize crystalline CTF-1 nanoribbons (CTF-1-NR). • The width of 1D nanoribbons can be facilely tuned by varying the solvent volume. • The CTF-1-NR are intercalated with Graphene Oxide (GO) membranes to enlarge water transport. • CTF-1-NR enhance photocatalytic ability compared to 2D nanosheets counterparts. • CTF-1-NR/GO membrane allows for recoverable permeability by solar illumination. Covalent triazine frameworks (CTFs) are drawing substantial interest as porous crystalline two-dimensional (2D) or three-dimensional (3D) nanomaterials. Fabrication of CTFs nanoribbon is challenging but appealing to separation and photocatalysis. Here we for the first time report the synthesis of crystalline CTF-1 nanoribbons (CTF-1-NR) comprising 2–3 covalent triazine framework units in width through a polar solvent-induced fragmentation strategy. The width of 1D nanoribbons can be facilely tuned by varying the solvent (e.g. ethanol) volume in trifluoromethanesulfonic acid layer after trimerization of aromatic nitriles. The CTF-1-NR are intercalated with Graphene oxide (GO) membranes to extend 1 H NMR transverse relaxation time (T 2 ) and enlarge the confined interspacing (∼8.8 Å), providing ultrafast water transport (∼60 L m -2 h −1 bar −1 ) and high dye molecules rejection (98%). More significantly, the bridging CTF-1-NR enhances charge-carrier separation and gains superior solar-cleaning recoverable permeability (∼7 folds higher than GO). This study provides novel insight into the synthesis of crystalline COF nanoribbons and membrane separation.