A superhydrophilic composite membrane with excellent photo-Fenton antifouling performance for efficient removal of diverse contaminants

The development of multifunctional composite membranes with integrating membrane separation and catalytic degradation processes is of great significance for effectively eliminating diverse contaminants from water. Herein, a superhydrophilic PANI/Fe1.02Zr-MOF/PVDF composite membrane was designed and prepared via nonsolvent induced phase separation (NIPS) method followed by in situ polymerization to coat a polyaniline (PANI) layer. The introduction of Fe-doped Zr-MOF (Fe1.02Zr-MOF) imparts an excellent self-cleaning ability to the membrane due to in situ photo-Fenton reaction. The surface modification with a PANI layer enhances the membrane's hydrophilicity and provides abundant active sites for contaminant enrichment. The composite membrane demonstrated remarkable removal efficiency towards a wide range of contaminants, including antibiotics, hexavalent chromium, and oil, as well as excellent antifouling ability. Moreover, continuous and rapid sewage purification was achieved by combining multiple membranes in a cascade configuration under a small additional pressure. The potential toxicities of intermediate products generated from the degradation of antibiotics were analyzed. The mechanisms involved in photo-Fenton degradation of antibiotic and photocatalytic reduction of Cr(VI) were studied. This work highlights a novel strategy to develop composite membranes with excellent photo-Fenton self-cleaning ability for efficient removal of diverse water contaminants.