Lamellar crosslinking reinforced strategy to prepare 2D metal-organic framework membranes for ultra-fast and robust molecules/ions separation

Abstract

Two-dimensional (2D) metal-organic framework (MOF) membranes have garnered significant attention for high throughput and precise molecular/ionic sieving. However, the delamination of lamellar nanosheet structure challenges the continuous separation under the intense fluid shear in real hydraulic pressure and cross-flow operation. Here we present a highly durable nickel-derived metal-organic framework (Ni-MOF) lamellar membrane stabilized by a polymer network of gallic acid (GA) and polyethyleneimine (PEI) for efficient ions/molecules separation. The crosslinked network construction reinforced the nanosheets interaction and contributed to the interlayer structure integrity, thus maintaining the Ni-MOF membrane a stable water permeance and nano/sub-nanometer selectivity (permeance >80 L m−2 h−1 bar−1, Sdye/NaCl>100) for 170 h under cross-flow, superior to most lamellar membranes under dead-end filtration. Moreover, the Ni-MOF membrane could withstand multiple bending and violent ultrasonic treatment (190 W). The lamellar crosslinking reinforced strategy is applicable to other lamellar MOF membranes, which offers a forward-looking strategy to tackle 2D membrane stability and facilitate practical applications for robust separation.