Porous Graphene-based Membranes: Preparation and Properties of a Unique Two-dimensional Nanomaterial Membrane for Water Purification

Fabrication of nanoporous membranes from two-dimensional nanomaterial has recently gained increased research interest because of their flexibility, freestanding film formability, selectivity, and ability to withstand the applied transmembrane pressure. Among various 2D materials, graphene and its derivatives are widely employed for the preparation of next-generation membranes due to their excellent separation properties with inherent qualities like atomic thickness, good tensile strength, and frictionless surface for real-time applications. This review discusses the recent progress in three types of porous graphene-based materials, which are holey graphene, graphene nanomesh and graphene oxide laminates, and their applicability for membrane separations. This review aims to summarize the preparation and properties of these membranes for water purification application. The various factors which influence the separation efficiency of the graphene-derived membranes such as mechanical stability, effect of surface architecture, effect of interlayer spacing, and various crosslinking strategies are also discussed.