Work

A covalent organic framework membrane with highly selective and permeable artificial sodium channels via ion recognition

Year: 2025

Type: article

Abstract: Biological sodium channels efficiently discriminate between same–charge ions with similar hydration shells. However, achieving precise ion selectivity and high throughput in artificial ion channel fabrication remains challenging. Here, we investigate angstrom–scale channels in 15-crown-5 (15C5) functionalized COF membranes for fast, selective ion transport. Due to crown ether recognition of sodium ions, channels in DHTA-Hz-15C5 membranes selectively facilitate Na+ transport, further enhanced by the hydroxyl-enriched COF skeleton. A Na+/K+ selectivity of 58.31 is achieved with 9.33 mmol m−2 h–1 permeance, significantly exceeding current membranes and resembling biological channels. Theoretical simulations indicate one–dimensional COF channels facilitate transport, while crown ether recognition makes the Na+ energy barrier significantly lower than K⁺, enabling ultrahigh selectivity with high Na⁺ permeability. This promotes COFs for efficient single-ion transport and advances crown ether ion selectivity in nano-restricted environments. Discriminating between ions with the same charge and similar hydration shells with artificial ion channels is challenging. Here, the authors produced crown ether functionalized covalent organic framework membranes for fast and selective sodium transport.

Source: Nature Communications

DOI: 10.1038/s41467-025-62329-1