Facile MXene-templated thin film composite membranes for enhanced nanofiltration performance

The eco-friendly and efficient nanofiltration (NF) membrane plays a critical role in the water purification industry; however, improving permeance while maintaining rejection remains a tremendous challenge. This study presents a novel approach for regulating interfacial polymerization (IP) by intercalating sodium alginate (SA) into MXene nanosheets. This method facilitates the fabrication of nanofiltration membranes that effectively overcome the "trade-off" effect. In addition to increasing the penetration area by enlarging the interlayer spacing between MXene nanosheets, the use of SA also reduces the susceptibility to swelling caused by weak interactions among adjacent stacked nanosheets. The presence of the intermediate layer effectively regulates the diffusion of piperazine and promotes the formation of a complete polyamide (PA) layer with ridge-valley structures, while simultaneously enhancing permeability. The permeability of the prepared nanofiltration membrane reaches 32.4 L m-2h- 1 bar- 1 while retaining a rejection efficiency of 96.3 % for divalent ions. This research paves the way for the development of a new generation of high-flux nanofiltration membranes used in desalination and water purification.