Layered covalent triazine frameworks can be exfoliated into 1–2 layered nanosheets via acid–base intercalation and subsequent oxidation exfoliation to obtain much improved specific capacitance and rate performance for Li ion battery anode.

Gene therapy is a revolutionary biomedical technique for the treatment of many diseases, and the development of safe and efficient intracellular gene delivery vectors is crucial for successful gene therapy. Herein, we report a strategy to construct dual-functionalized covalent triazine framework-poly­(ethylene glycol)-polyethylenimine (CTF-PEG-PEI) nanosheets as nonviral vectors via exfoliation and surface chemistry modification. Benefiting from the unique brushlike hierarchical structure, CTF-PEG-PEI can strongly condense nucleic acids and efficiently release the nucleic acid cargo after cellular uptake. Systematic gene delivery studies in both 293T and HeLa cells demonstrate that CTF-PEG-PEI has superior gene transfection performance and lower cytotoxicity compared with polyethylenimine (PEI), especially at low dosages.

The hierarchical structure enhances oxygen diffusion, improves electron transfer, and exposes more catalytic active sites for the ORR.