Recent Advances in Graphene Oxide-Based Membranes for Heavy Metal Ions Separation

Graphene oxide (GO)-based membranes have been widely investigated for separation of dyes, salt ions, heavy metal ions, and biomolecules due to their high mechanical strength, single-layered structure, large surface area, and high affinity. However, due to irregular pore structure, nanochannels, interlayer distance, easy functionalization, swelling effect, and chemical stability under aqueous environment limited their separation efficiency. In this review, different fabrication methods of GO membranes are summarized. The role of functionalization and cross-linking on membrane's structural properties, separation performance, and practical applications are discussed. Further, the GO-based membranes (GOMs) for separation and removal of heavy metal ions are discussed in detail. The factors which influence the separation performance are also highlighted. Finally, recommendations and future directions are suggested.