High-permeable graphene oxide/graphitic carbon nitride composite nanofiltration membrane for selective separation of dye and desalination

High permeable and selectivity nanofiltration membranes are desirable for water treatment. Recently graphene oxide (GO) membrane has emerged as a promising nanofiltration material, however, its low permeability and poor selectivity limit its application in nanofiltration. To this end, we used GO nanosheets with abundant functional groups to modify graphitic carbon nitride (g-C3N4) as a support material in GO membranes, and prepared nanofiltration membranes with laminated stacks. With reasonable modification, the water permeability of membrane is as high as 274.7 L center dot m(-2)center dot h(-1)center dot bar(-1), which is 11.5 times that of GOM. For cationic/anionic mixed dyes to achieve selective separation, it has different repelling properties for divalent/monovalent salt ions, and has good stability. This research shows that GO modified g-C3N4 is an effective additive for the development of novel GO membranes, which provides a new reference for the use of stable and reliable nanofiltration membranes in aqueous environments.

Automated summary

Graphene oxide (GO) modified graphitic carbon nitride (g-C3N4) was used as a support material to prepare laminated nanofiltration membranes. The modified membranes showed a water permeability of 274.7 L center dot m(-2)center dot h(-1)center dot bar(-1), which was 11.5 times higher than that of GO membranes. The membranes also exhibited excellent selectivity and stability. This study provides a new reference for the development of stable and reliable nanofiltration membranes in water treatment.