COF Scaffold Membrane with Gate-Lane Nanostructure for Efficient Li+/Mg2+ Separation

Covalent organic framework (COF) scaffold membranes with gate-lane nanostructure were prepared. The gating layer affords high rejection to Mg 2+ and thus high Li + /Mg 2+ selectivity. The permeating layer bearing Li + lanes and Cl − lanes facilitates Li + transport and thus high Li + permeability. The COF scaffold membrane exhibits the true selectivity of 231.9 with Li + enrichment of 120.2% at the Mg 2+ /Li + mass ratio of 50, exceeding the ideal selectivity of 80.5.