Design and engineering of graphene oxide (GO) based framework membranes for water treatment via nanofiltratio

Facing an immense necessity to explore cost-effective and highly efficient water reuse technologies, nanofiltration (NF) has emerged as a promising wastewater treatment method for its low footprint. To advance this technology, next-generation membranes based on graphene oxide (GO) materials has been initiated and established. Novel modification strategies, including (1) the crosslinking and construction of a rigid GO framework and (2) the amine-enrichment modification, have been proposed to design stable and highly charged GO framework membranes with the GO selective layer thickness of less than 100 nm for effective heave metal and dye removal via NF process. Results from sonication experiments and positron annihilation spectroscopy confirmed that crosslinking not only enhanced structural stability, but also enlarged the nanochannels among the laminated GO nanosheets for higher water permeability. The permeability of the newly developed GO membranes outperforms polymeric membranes by 4 times. GO hollow fiber configuration was also designed to scale up the membrane fabrication process, which is a breakthrough in wastewater treatment and has great potential for industrial applications.