Improvements in multifunctional graphene oxide-based separation membranes: Mechanism, modification and properties

Graphene oxide (GO) is a derivative of graphene. Compared with graphene, GO has abundant oxygen-containing functional groups such as hydroxyl and carboxyl groups, which impart good mechanical properties and hydrophilicity. Therefore, GO is widely used in the field of membrane separation. In this paper, we introduce the separation mechanisms of GO membranes and discuss in detail their applications in water filtration, gas separation, and removal of metal ions and dye molecules. We also discuss methods for tuning the properties of GO membranes, including reduction, physical intercalation, and chemical modification to control the layer spacing of GO films. Finally, improvements to the hydrophilicity and antibacterial properties of the modified films are introduced, and the prospects for future development of GO films are discussed. Overview of GO film modifications and properties discussed in this review. The separation mechanism, the method of regulating layer spacing, and the properties after modification are reviewed. The inner part of the figure describes the separation mechanism, the upper part of the figure describes methods of regulating membrane spacing, and the lower part of the figure describes the performance after modification.