g-C3N4 nanofibers network reinforced polyamide nanofiltration membrane for fast desalination

Enhancing the water permeability of reverse osmosis and nanofiltration (NF) membranes without sacrificing the quality of water production can potentially lead to substantial savings in cost and has considerable practical impact on broad application. Herein, we report a facile fabrication of thin film composite (TFC) NF membrane with crumple polyamide (PA) active layer based on a graphitic carbon nitride (g-C3N4) nanofibers network interlayer via interfacial polymerization, where the g-C3N4 nanofibers network film is formed simultaneously with the formation of PA active layer by a self-deposition process. The special g-C3N4 nanofibers network film possesses ultra-high hydrophilicity, high porosity and relative smooth surface, which is favorable to form a defect-free and crumple PA active layer. The g-C3N4 nanofibers network interlayer assisted TFC NF membrane exhibits a high water flux up to 152 L m-2h−1 (4 bar) while maintains a high salt rejection with Na2SO4 rejection of 98.9%.