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

Abstract

Two-dimensional (2D) lamellar membranes have attracted increasing attention for efficient water purification. However, the low water-permeability, structural failure in aqua and high production cost have significantly restricted their practical large-scale applications. Inspired by the structures of glomerular filtration barrier (GFB) and nacre, a high-performance biomimic membrane via supramolecular-mediated intercalation assembly is reported, where rod-shaped cyclodextrin (CD) functionalized attapulgite (ATP-CD) is intercalated into CD-modified graphene oxide (GO-CD) lamellar channels, followed by locking adjacent ATP-CD and GO-CD through tannic acid (TA) and CD supramolecular networks. The formed GFB-like heterostructure endows the membrane with excellent water transport capability and the bionic "brick and mortar" nacre configuration boosts its anti-swelling stability simultaneously. The heterostructured GO membranes (≈100nm) fabricated in this way exhibit a good water permeability of 55.6Lm-2 h-1 bar-1 (≈20-fold higher than GO membrane) maintaining excellent dye rejection of >99% during 480h immersion. Given the low-cost materials (ATP, CD, and TA) and the modification generality, this economic strategy can hopefully achieve large-scale membrane fabrication and afford high applicability, which promotes the practical engineering applications of such 2D material membranes.