Graphene oxide membranes: Functional structures, preparation and environmental applications

Graphene oxide (GO) membranes, as laminated and channel-rich architectures assembled by stacked GO nanosheets, have surpassed other two-dimensional (2D) nanomaterials and present preeminent structural specialization and potential applicability in a wide range of environmental applications. This review mainly surveys the latest GO-based macroscopic membranes, which feature distinct functionalized structures, interior fluid flows, and tunable physicochemical properties. The GO-based membranes are classified and presented in three typical forms: single-layered porous GO membranes, few-layered laminated GO membranes, and multi-layered composited GO membranes. More attention is paid to target-oriented preparation strategies for the assembly of GO building blocks, involving multiple interactions and technical advantages, and to the resulting membrane characteristics. The overview also explores the serviceability of these GO-based membranes for full-scale use in environmental practices in gas, water, and biological treatments to pave the way for the promising development and realization of their prospects.