Defect-Modified NH2-MIL-88B Improves Catalytic Self-Cleaning Properties of Thin Film Nanocomposite (TFN) Membranes

The high activity and easy recyclability of catalysts are significant challenges in the photocatalytic treatment of wastewater. Combining photocatalytic technology with membrane separation technology to prepare self-cleaning catalytic composite membranes for treating wastewater containing organic pollutants can not only solve the problem of traditional catalyst recovery difficulties but also overcome membrane fouling. In this paper, NH 2 -MIL-88B was modified by introducing citric acid as a ligand construction defect, and NH 2 -MIL-88B-CA (NMB-CA) with better photocatalytic performance was obtained. Then, a thin film nanocomposite (TFN) film with better self-cleaning performance was prepared by covalently bonding the NMB-CA nanocatellite to the active polyamide layer through interfacial polymerization and amidination in Polysulfone (PSF) based membrane. The best-performing TFN-2 membrane has even better fouling resistance, removing 98.1% of tetracycline after 8 cycles, and the water flux of the membrane can still recover to 99% of the initial water flux, demonstrating excellent recyclability. TFN membrane prepared in this paper has unique self-cleaning and anti-pollution characteristics, which provides a new solution for efficient treatment of organic-contaminated water.