Rapid and Scalable Channel‐End‐Sealing Assembly of Flexible 20‐nm Co‐Continuous MOF Membranes for Ultrafast Gas Separation

ABSTRACT Metal‐organic framework (MOF) membranes with sub‐nanometer pore systems hold great potential for efficient gas separations. However, the rational designing and scalable manufacturing of MOF membranes face critical challenges, including stringent synthesis conditions, prolonged processing times, excessive reagent consumption, limited scalability, poor reproducibility, uncontrollable thickness, and mechanical fragility. In this study, we report a bioinspired channel‐end‐sealing assembly strategy for facile, rapid, and scalable production of flexible, ultrathin (≈20 nm), large‐area (>1000 cm 2 ) co‐continuous MOF membranes. Inspired by capping the unit cells of honeycombs, we present sealing the channel ends of polymer substrates to form defect‐free membranes, through establishing controllable and self‐terminating crystallization at the nanoconfined interfaces between biphasic precursor systems via stoichiometric modulation. This strategy enables reproducible manufacturing of MOF membranes within 5 min at room temperature with low precursor consumption of 1.0 mL cm −2 . Moreover, the resulting MOF membranes exhibit ultrafast and stable sieving properties with H 2 permeance as high as 13900 gas permeation units and H 2 /CO 2 selectivity up to 40.6 at 150 °C, outperforming state‐of‐the‐art membranes. Crucially, the membranes can maintain their performance after bending with a curvature of 200 m −1 . These findings pave the way for industrial‐scale production and application of MOF membranes.