Fundamental Transport Mechanisms and Advancements of Graphene Oxide Membranes for Molecular Separation

Graphene shows excellent mechanical, electrical, and optical properties. Its unique structure and attributes have made it and its derivatives (e.g., graphene oxide (GO) and reduced graphene oxide (rGO)) promising candidates in molecular separation. Excellent molecular separation performance, including permeability and selectivity, has been demonstrated by GO membranes recently. In this review, the mechanisms, i.e., in-plane pores (defects), interlayer spacing, and functional group assisted molecular separation, of selective molecular transport through GO membranes are summarized. In addition, preparation and interlayer spacing tuning strategies of GO membranes are provided. This timely review aims to present the latest advancements in both the theoretical and experimental demonstration of GO membranes for molecular separation. Moreover, current challenges and emerging perspectives of GO membranes for separation are also discussed.