Facile tailoring of the two-dimensional graphene oxide channels for gas separation

Two dimensional graphene-basedmaterials with unique atomic thickness and excellent mass transport properties are gaining heightened attention for the development of a new family of separation membranes. As a derivative of graphene, graphene oxide (GO) is now considered as a promising nano-building block for membranes, owing to its tunable microstructures and physiochemical properties as well as large-scale fabrication using a solution-based strategy. Through facile oxidization and exfoliation of bulk graphite, a large number of oxygenated functionalities can be chemically bonded on both basal planes and sheets edges of carbon layers, endowing the two dimensional (2D) GO nanosheets with rich chemistry property. As a result, it has been well demonstrated that GO-based membranes with well-assembled laminar structure can be engineered to provide nanochannels for selective molecular transport. This leads to a success application of GO-based membranes in water treatment due to the highly hydrophilic characteristic. Generally, separation properties of membrane can be nely tuned by materials nanostructure. As a result, most of the studies focused on controlling the stacking structure of GO laminates to optimize the membrane separation performance. Aer being dispersed in water solution, GO nanosheets are assembled into laminates using methods based on mechanical external forces such as dip-coating, ltration and spin-coating. However, it has been proven that the