High-Throughput Electrochemical Delamination of Two-Dimensional Covalent Organic Frameworks

Porous crystalline nanosheets of two-dimensional covalent organic frameworks (2D COFs) possess intriguing structural features and extensive application potential. However, the scalable and efficient synthesis of well-crystallized COF nanosheets remains challenging despite recent advances in exfoliation and in situ growth techniques. Here we report a high-throughput electrochemical strategy that nondestructively delaminates polycrystalline 2D COF films into large nanosheets with long-range crystallographic order. This method achieves a remarkable delamination productivity of 100 mg h^-1, yielding crystalline nanosheets that are readily dispersible across various solvents including water. Principal component analysis reveals solvent permittivity and polarity, along with film wettability, as critical factors governing the delamination efficiency. Complementary diffraction, spectroscopy, and electron microscopy studies elucidate a synergistic delamination mechanism involving molecular preintercalation, framework protonation, and electrolysis-driven gas evolution. Leveraging the intrinsic microporosity and excellent solution processability of these nanosheets, we demonstrate their utility in producing membranes for efficient antibiotic desalination. This work advances the scalable synthesis of crystalline COF nanosheets, broadening the application toolkit of COFs.