Biomimetic Helical Hydrogen Bonded Organic Framework Membranes for Efficient Uranium Recovery from Seawater

Abstract Inspired by the uranyl‐imidazole interactions via nitrogen's (N's) of histidine residues in single helical protein assemblies with open framework geometry that allows through migration/coordination of metal ions. Here, preliminary components of a stable hydrogen‐bonded organic framework (HOF) are designed to mimic the stable single helical open framework with imidazole residues available for Uranium (U) binding. The imidazolate‐HOF ( CSMCRI HOF2‐S) is synthesized with solvent‐directed H‐bonding in 1D array and tuned hydrophobic CH–π interactions leading to single helix pattern having enhanced hydrolytic stability. De‐solvation led CSMCRI HOF2‐P with porous helical 1D channels are transformed in a freestanding thin film that showcased improved mass transfer and adsorption of uranyl carbonate. CSMCRI HOF2‐P thin film can effectively extract ≈14.8 mg g −1 in 4 weeks period from natural seawater, with > 1.7 U/V (Uranium to Vanadium ratio) selectivity. This strategy can be extended for rational designing of hydrolytically stable, U selective HOFs to realize the massive potential of the blue economy toward sustainable energy.