Selective Ion Permeation through Stabilized Metal–Phenolic Grafted Graphene Oxide Membranes

Abstract The structural stability and high permeability of 2D materials‐based membranes are key research interests for separation membranes. However, the instability of their microstructures due to the aqueous‐induced swelling phenomenon affects their performance. It is highly desirable to explore anti‐swelling approaches able to mitigate this challenge as well as develop 2D lamellar membranes with ion selective capabilities beyond the limits based on size exclusion mechanism. Herein, graphene oxide (GO) laminate membranes covalently anchored and intercalated with metal‐phenolic networks display suppressed swelling durability and resist delamination in aqueous media. The resultant Fe@TA‐GO membrane with confined d‐spacing boasts high water fluxes of up to 15.0 L m⁻² h⁻¹ under osmotic pressure (2 m sucrose). Furthermore, the permeation tests reveal that the interaction between the metal ions and the immobilized cation–ligand molecules influences the ion permeances through the functionalized GO membranes conducing to fast ion permeation rates with ion diffusion permselectivity as well as effective selective separation of organic contaminants. These results will help advance the applications of GO membranes for challenging ion separations related to sustainable resource recovery and environmental remediation of organic dye and metal ion contaminated wastewaters.