Chemically Laminating Graphene Oxide Nanosheets with Phenolic Nanomeshes for Robust Membranes with Fast Desalination.

Abstract

Graphene oxide (GO) is receiving tremendous attention in membrane separation; however, its desalination performances remain suboptimal because of excessive swelling and tortuous transport pathways. Herein, we chemically joint GO nanosheets and phenolic nanomeshes together to form laminated membranes comprising through-plane nanopores and stabilized nanochannels. GO and phenolic/polyether nanosheets are mixed to form stacked structures and then treated in H₂SO₄ to remove polyether to produce nanomeshes and to chemically joint GO with phenolic nanomeshes. Thus-synthesized laminated membranes possess enhanced interlayer interactions and narrowed interlayer spacings down to 6.4 Å. They exhibit water permeance up to 165.6 L/(m² h bar) and Na₂SO₄ rejection of 97%, outperforming most GO-based membranes reported so far. Moreover, the membranes are exceptionally stable in water because the chemically jointed laminates suppress the swelling of GO. This work reports hybrid laminated structures of GO and phenolic nanomeshes, which are highly desired in desalination and other applications.