Abstract
Biological ion channels exemplify nature’s high-efficiency ion selectivity filters, yet replicating their functional architectures in synthetic membranes remains a fundamental challenge. Here, we report an ultramicroporous hydrogen-bonded organic framework membrane that structurally emulates the CLC chloride filter. Its channels exhibit size adaptability to anions and incorporate hydrogen-bond donors that provide “low-viscosity” compensatory interactions, thereby alleviating anion dehydration energy penalties. By leveraging differential dehydration and energy compensation between Cl− and larger anions such as SO42−, this bioinspired design achieves an exceptional Cl−/SO42− selectivity of over 400—several tens of times higher than those of existing counterparts—while maintaining a high Cl− permeation rate double that of the commercial Neosepta® ACS membrane, setting a new benchmark for advanced anion-sieving membranes. In electrodialysis (ED) for high-salinity wastewater valorization, our membrane enables higher NaCl product purity (99.62 wt% vs. 72.86 wt%) with 28.7% lower energy consumption than the Neosepta® ACS membrane. This work establishes a biomimetic design principle of biological anion channels that is potentially extendable to a wide range of selective and conductive membranes.
Data availability
The authors confirm that the data supporting the findings of this study are available within the article and its supplementary information. All data are available from the corresponding author upon request.
References
Xie, X. et al. Microstructure and surface control of MXene films for water purification. Nat. Sustainability 2, 856–862 (2019).
Bolisetty, S. & Mezzenga, R. Amyloid–carbon hybrid membranes for universal water purification. Nat. Nanotechnol. 11, 365–371 (2016).
Huang, J. et al. Sustainable nanofiltration membranes enable ultrafast water purification. Nat. Water 3, 1048–1056 (2025).
Wang, Y., Lian, T., Tarakina, N. V., Yuan, J. & Antonietti, M. Lamellar carbon nitride membrane for enhanced ion sieving and water desalination. Nat. Commun. 13, 7339 (2022).
Zhang, X. et al. Electrodialytic crystallization to enable zero liquid discharge. Nat. Water 1, 547–554 (2023).
Xu, X. et al. Nanofiltration membranes with ultra-high negative charge density for enhanced anion sieving and removal of organic micropollutants. Nat. Water 3, 704–713 (2025).
Zhao, C. et al. Polyamide membranes with nanoscale ordered structures for fast permeation and highly selective ion-ion separation. Nat. Commun. 14, 1112 (2023).
Jentsch, T. J., Stein, V., Weinreich, F. & Zdebik, A. A. Molecular structure and physiological function of chloride channels. Physiol. Rev. 82, 503–568 (2002).
Miller, C. CLC chloride channels viewed through a transporter lens. Nature 440, 484–489 (2006).
Leisle, L. et al. Backbone amides are determinants of Cl− selectivity in CLC ion channels. Nat. Commun. 13, 7508 (2022).
Paulino, C., Kalienkova, V., Lam, A. K. M., Neldner, Y. & Dutzler, R. Activation mechanism of the calcium-activated chloride channel TMEM16A revealed by cryo-EM. Nature 552, 421–425 (2017).
Dutzler, R., Campbell, E. B. & MacKinnon, R. Gating the selectivity filter in CLC chloride channels. Science 300, 108–112 (2003).
Abraham, J. et al. Tunable sieving of ions using graphene oxide membranes. Nat. Nanotechnol. 12, 546–550 (2017).
Kang, Y. et al. Nanoconfinement enabled non-covalently decorated MXene membranes for ion-sieving. Nat. Commun. 14, 4075 (2023).
Mo, R.-J. et al. Regulating ion affinity and dehydration of metal-organic framework sub-nanochannels for high-precision ion separation. Nat. Commun. 15, 2145 (2024).
Meng, Q.-W. et al. Guanidinium-based covalent organic framework membrane for single-acid recovery. Sci. Adv. 9, eadh0207 (2023).
Meng, Q.-W. et al. Optimizing selectivity via membrane molecular packing manipulation for simultaneous cation and anion screening. Sci. Adv. 10, eado8658 (2024).
Yan, T. & Liu, J. Transmembrane ion channels: from natural to artificial systems. Angew. Chem. Int. Ed. 64, e202416200 (2025).
Wu, Y. et al. 2D molecular sheets of hydrogen-bonded organic frameworks for ultrastable sodium-ion storage. Adv. Mater. 33, 2106079 (2021).
Chen, C. et al. Hydrogen-bonded organic frameworks for membrane separation. Chem. Soc. Rev. 53, 2738–2760 (2024).
Shang, X. et al. Chiral self-sorted multifunctional supramolecular biocoordination polymers and their applications in sensors. Nat. Commun. 9, 3933 (2018).
Feng, S. et al. Fabrication of a hydrogen-bonded organic framework membrane through solution processing for pressure-regulated gas separation. Angew. Chem. Int. Ed. 59, 3840–3845 (2020).
Yin, Q. et al. Hydrogen-bonded organic frameworks in solution enables continuous and high-crystalline membranes. Nat. Commun. 15, 634 (2024).
Wang, Y., Song, L.-N., Wang, X.-X., Wang, Y.-F. & Xu, J.-J. Hydrogen-bonded organic frameworks-based electrolytes with controllable hydrogen bonding networks for solid-state lithium batteries. Angew. Chem. Int. Ed. 63, e202401910 (2024).
Wang, J. et al. In situ assembly of hydrogen-bonded organic framework on metal–organic framework: an effective strategy for constructing core–shell hybrid photocatalyst. Adv. Sci. 9, 2204036 (2022).
Meng, W. et al. Three-dimensional cationic covalent organic framework membranes for rapid and selective lithium extraction from saline water. Nat. Water 3, 191–200 (2025).
Park, H. B., Kamcev, J., Robeson, L. M., Elimelech, M. & Freeman, B. D. Maximizing the right stuff: The trade-off between membrane permeability and selectivity. Science 356, eaab0530 (2017).
Wang, H. et al. Covalent organic framework membranes for efficient separation of monovalent cations. Nat. Commun. 13, 7123 (2022).
Xu, R., Kang, Y., Zhang, W., Zhang, X. & Pan, B. Oriented UiO-67 metal–organic framework membrane with fast and selective lithium-ion transport. Angew. Chem. Int. Ed. 61, e202115443 (2022).
Hong, Z. et al. Rigid and flexible coupled micropore membranes enabling ultra-efficient anion separation. AlChE J. 71, e18803 (2025).
Lu, C. et al. Dehydration-enhanced ion-pore interactions dominate anion transport and selectivity in nanochannels. Sci. Adv. 9, eadf8412 (2023).
Richards, L. A., Richards, B. S., Corry, B. & Schäfer, A. I. Experimental energy barriers to anions transporting through nanofiltration membranes. Environ. Sci. Technol. 47, 1968–1976 (2013).
Zhou, X. et al. Intrapore energy barriers govern ion transport and selectivity of desalination membranes. Sci. Adv. 6, eabd9045 (2020).
Richards, L. A., Schäfer, A. I., Richards, B. S. & Corry, B. Quantifying barriers to monovalent anion transport in narrow non-polar pores. Phys. Chem. Chem. Phys. 14, 11633–11638 (2012).
Chandra, A. Effects of ion atmosphere on hydrogen-bond dynamics in aqueous electrolyte solutions. Phys. Rev. Lett. 85, 768–771 (2000).
Liu, M.-L. et al. Microporous membrane with ionized sub-nanochannels enabling highly selective monovalent and divalent anion separation. Nat. Commun. 15, 7271 (2024).
Epsztein, R., DuChanois, R. M., Ritt, C. L., Noy, A. & Elimelech, M. Towards single-species selectivity of membranes with subnanometre pores. Nat. Nanotechnol. 15, 426–436 (2020).
Ries, L. et al. Enhanced sieving from exfoliated MoS2 membranes via covalent functionalization. Nat. Mater. 18, 1112–1117 (2019).
Kitto, D. et al. Fast and selective ion transport in ultrahigh-charge-density membranes. Nat. Chem. Eng. 2, 252–260 (2025).
Feng, L., Tian, B., Zhu, M. & Yang, M. Current progresses in the analysis, treatment and resource utilization of industrial waste salt in China: a comprehensive review. Resour. Conserv. Recycl. 217, 108224 (2025).
Wang, T. et al. Low-salt-rejection reverse osmosis membranes decrease energy consumption and economic cost in a wastewater zero liquid discharge system. Desalination 620, 119629 (2026).
Zhang, X. et al. Production of yellow iron oxide pigments by integration of the air oxidation process with bipolar membrane electrodialysis. Ind. Eng. Chem. Res. 53, 1580–1587 (2014).
He, D. et al. Bipolar membrane electrodialysis with isolation chamber enables high-purity LiOH production with ordinary membranes. AlChE J. 71, e18674 (2025).
Lu, D. et al. Impact of charge homogeneity on ion selectivity in polyamide membranes. Nat. Water 3, 978–991 (2025).
Zhang, Y. et al. Ice-confined synthesis of highly ionized 3D-quasilayered polyamide nanofiltration membranes. Science 382, 202–206 (2023).
Irfan, M., Ge, L., Wang, Y., Yang, Z. & Xu, T. Hydrophobic side chains impart anion exchange membranes with high monovalent–divalent anion selectivity in electrodialysis. ACS Sustain. Chem. Eng. 7, 4429–4442 (2019).
Xu, T. et al. Scalable and interfacial gap-free mixed matrix membranes for efficient anion separation. AlChE J. 70, e18242 (2024).
Liao, J. et al. Amphoteric ion-exchange membranes with superior mono-/bi-valent anion separation performance for electrodialysis applications. J. Membr. Sci. 577, 153–164 (2019).
Liao, J. et al. Monovalent anion selective anion-exchange membranes with imidazolium salt-terminated side-chains: Investigating the effect of hydrophobic alkyl spacer length. J. Membr. Sci. 599, 117818 (2020).
Li, J. et al. The endowment of monovalent anion selectivity and antifouling property to cross-linked ion-exchange membranes by constructing amphoteric structure. Sep. Purif. Technol. 328, 125104 (2024).
Xiao, X. et al. Anion permselective membranes with chemically-bound carboxylic polymer layer for fast anion separation. J. Membr. Sci. 614, 118553 (2020).
Li, M. et al. Polyvinyl alcohol-based monovalent anion selective membranes with excellent permselectivity in selectrodialysis. J. Membr. Sci. 620, 118889 (2021).
Wang, C. et al. Effect of microstructures of side-chain-type anion exchange membranes on mono-/bivalent anion permselectivity in electrodialysis. ACS Appl. Polym. Mater. 3, 342–353 (2021).
Lejarazu-Larrañaga, A., Zhao, Y., Molina, S., García-Calvo, E. & Van der Bruggen, B. Alternating current enhanced deposition of a monovalent selective coating for anion exchange membranes with antifouling properties. Sep. Purif. Technol. 229, 115807 (2019).
Liao, J. et al. Amphoteric blend ion-exchange membranes for separating monovalent and bivalent anions in electrodialysis. Sep. Purif. Technol. 242, 116793 (2020).
Liao, J. et al. Long-side-chain type imidazolium-functionalized fluoro-methyl poly(arylene ether ketone) anion exchange membranes with superior electrodialysis performance. J. Membr. Sci. 574, 181–195 (2019).
Yang, H. et al. Poly(alkyl-biphenyl pyridinium) anion exchange membranes with a hydrophobic side chain for mono-/divalent anion separation. Ind. Chem. Mater. 1, 129–139 (2023).
Li, J. et al. Revolutionary MOF-enhanced anion exchange membrane for precise monovalent anion separation through structural optimization and doping. Desalination 576, 117352 (2024).
Pan, J. et al. One-pot approach to prepare internally cross-linked monovalent selective anion exchange membranes. J. Membr. Sci. 553, 43–53 (2018).
Goel, P. et al. Di-quaternized graphene oxide based multi-cationic cross-linked monovalent selective anion exchange membrane for electrodialysis. Sep. Purif. Technol. 276, 119361 (2021).
Jiang, C. et al. Fouling deposition as an effective approach for preparing monovalent selective membranes. J. Membr. Sci. 580, 327–335 (2019).
Tekinalp, Ö, Zimmermann, P., Burheim, O. S. & Deng, L. Designing monovalent selective anion exchange membranes for the simultaneous separation of chloride and fluoride from sulfate in an equimolar ternary mixture. J. Membr. Sci. 666, 121148 (2023).
Afsar, N. U. et al. In-situ interfacial polymerization endows surface enrichment of -COOH groups on anion exchange membranes for efficient Cl−/SO42− separation. J. Polym. Sci. 60, 3022–3034 (2022).
Ahmad, M., Tang, C., Yang, L., Yaroshchuk, A. & Bruening, M. L. Layer-by-layer modification of aliphatic polyamide anion-exchange membranes to increase Cl−/SO42− selectivity. J. Membr. Sci. 578, 209–219 (2019).
You, X. et al. Charged nanochannels in covalent organic framework membranes enabling efficient ion exclusion. ACS Nano 16, 11781–11791 (2022).
Acknowledgements
This work was supported by the National Key R&D Program of China (No. 2022YFB3805100 [J.R.]), the National Natural Science Foundation of China (No. 22278105 [J.R.]), the Fundamental Research Funds for the Central Universities (No. YD2060002046 [P. Z.]), and the Distinguished Young Scholars Program of Anhui Province (No. 2408085J010 [P. Z.]). The computation is completed on the HPC Platform of Hefei University of Technology. The analysis work of this article was partially carried out at the Instrumental Analysis Center, Hefei University of Technology.
Author information
Authors and Affiliations
Contributions
J.R., P.Z., and T.X. conceived the idea and designed the experiments. S.Z. carried out the material synthesis, characterization, and performance tests. Z.W. and C.F. performed the MD simulations. X.Z., G.L., Q.Z., and P.C. contributed to the data curation and investigation. S.Z. and Z.W. performed the data analysis. All coauthors discussed the results. S.Z. and P. Z. wrote the manuscript. J.R., P.Z., and T.X. revised the manuscript.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Peer review
Peer review information
Nature Communications thanks Liguo Shen and the other, anonymous, reviewers for their contribution to the peer review of this work. A peer review file is available.
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary information
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
About this article
Cite this article
Zhang, S., Wan, Z., Zhang, X. et al. Engineering biomimetic chloride channels in ultramicroporous hydrogen-bonded organic framework membranes for high-salinity wastewater valorization. Nat Commun (2026). https://doi.org/10.1038/s41467-026-69947-3
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41467-026-69947-3
