Magnetism-driven fabrication of polyamide nanofiltration membranes with enhanced antibiotic removal and photocatalytic properties

Inspired by the use of magnetism to shape material forms, this work presents a magnetism-driven approach to construct polyamide nanofiltration membranes with embedded magnetic Fe 3 O 4 –SnO 2 nanoparticles. A magnetic field is applied in the interfacial polymerization to attract magnetic nanoparticles from the aqueous phase to the water‒oil interface, forming a novel “template interface” that outlines the nanoparticles in the resulting membrane. This modification significantly enhanced the membrane performance, with a pure water flux of 27.2 L m −2  h −1 bar −1 , nearly quadrupling that of the TFC membrane, and 99.3 % Na 2 SO 4 rejection occurred resulting from reduced PA layer thickness, enlarged surface area, lower crosslinking degree, and enhanced surface hydrophilicity. Importantly, the incorporation of Fe 3 O 4 –SnO 2 nanoparticles endows the membrane with exceptional photocatalytic capabilities, which are crucial for degrading antibiotics adsorbed on the membrane surface and thereby restoring its separation performance. This approach regulates the morphology and performance of polyamide membranes, equipping them with advanced functionalities to address environmental pollution and water treatment challenges effectively.