Dual-confined metal-organic framework membrane with synergistic regulation for high-efficiency Li+/Mg2+ sieving

Innovatively developed an “adhesion-assisted growth” strategy for fabricating MOF membranes. • Constructed dual-confined ion channels enabling highly selective lithium-ion transport. • Implemented seed implantation in the adhesive layer to induce rapid and well-ordered MOF growth. • Established interconnected interface architecture forming continuous ion transport networks. • The developed membrane exhibits excellent long-term operational stability. Membranes featuring ordered biomimetic ion channels have been widely explored for ion-sieving applications, such as lithium extraction from salt-lake brines, seawater desalination, and energy conversion. However, achieving high ion permselectivity while enabling scalable fabrication for industrial use remains a major challenge. Here, we report a dual-confined metal-organic framework (MOF) membrane fabricated via an “adhesion-assisted growth” strategy. By integrating biomimetic ion channels functionalized with acidic groups, precise pore-size control, and surface chemical modulation, the membrane establishes a dual-nanoconfined separation system that simultaneously enables efficient Li + transport and effective Mg 2+ rejection. This specially designed adhesive layer not only promotes the well-defined formation of the MOF layer but also creates an interconnected ion transport network, thereby accelerating ion migration during selective electrodialysis (SED). Consequently, the resulting MOF membrane achieves a Li + flux of 1.17 mol·m −2 ·h −1 and exhibits a Li + /Mg 2+ permselectivity 14.3 times higher than that of the unmodified membrane, alongside excellent long-term operational stability. This environmentally friendly lithium extraction strategy advances the development of high-performance separation membranes and holds great promise for key applications such as lithium recovery from salt-lake brines, offering an innovative technological pathway toward efficient strategic resource recovery and the advancement of a circular economy. The synergistic dual-confined mechanism governs the selective Li + /Mg 2+ sieving performance of the MOF membrane. Download: Download high-res image (146KB) Download: Download full-size image