Interfacial interaction mediated diclofenac removal by Fe-MOFs catalytic filtration nanocellulose membrane via peroxodisulfate activation

The development of catalytic filtration membrane with high permeability, selectivity and antifouling performance remained challenging. This study fabricated a NH₂-MIL-101(Fe)@ cellulose nanofiber (MIL@CNF) membrane. The introduced NH₂-MIL-101(Fe) might well-enhance the pore size and smoothness of the membrane surface. The water flux of developed membranes were elevated by 2.56–9.13 times with MOFs incorporation owing to rich porous structure, less transmembrane resistance and increased hydrophilicity. The 30-MIL@CNF (MOFs:CNF = 30 %) had the optimal retention (54.5 %) and oxidization properties (89.5 %) for diclofenac (DCF). The oxidation process effectively inhibited fouling on both surfaces and inside pores due to higher peroxodisulfate (PDS) activation ability. Based on the Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, 30-MIL@CNF and DCF were more inclined to interact with each other via acid-base interactions. Density functional theory (DFT) results showed that MOFs and DCF tended to be hydrogen bonded. Composite membrane predominantly achieved DCF degradation through non-radical pathways (¹O₂ and direct electron transfer). High mineralization efficiency (74.95 %) from TOC results indicated excellent catalytic oxidation performance. The sustainable membrane with both filtration and advanced oxidation functionalities may provide underlying insights for the development of green catalytic filtration system.