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.

Biomimic Heterostructured Graphene Oxide Membranes via Supramolecular‐Mediated Intercalation Assembly for Efficient Water Transport

“…The GATm exhibits a decreased intensity of carboxyl groups (CO at 1735 cm –1 ) and an increased intensity of ester groups (C–O at 1195 cm –1 ) due to the esterification reaction between GO‐CD nanosheets and TA molecules. [ 18 a, 20 ] The O/C ratio of the GATm surface increases compared to GAm, demonstrating the formation of TA coating (Figure S9, Supporting Information). The C(O)‐O/C‐N ratio of GATm increases compared to GAm (Figure S10, Supporting Information), also suggesting the implementation of covalent modification.…”