Synergistic integration of NiFe-MOF and carbon quantum dots for multifunctional nanofiltration membranes with high permeability and photocatalytic self-cleaning

Industrial effluents containing persistent organic contaminants such as synthetic dyes and antibiotics are escalating global crises. Although membrane filtration offers an energy-efficient solution, its long-term performance is severely limited by fouling and the inherent permeability–selectivity dilemma. Herein, we propose a synergistic strategy to overcome these challenges by developing photocatalytic self-cleaning nanofiltration membranes through the incorporation of NiFe-MOF/CQD nanocomposites via interfacial polymerization. The introduced carbon quantum dots (CQDs) not only enhance the hydrophilicity and dispersibility of NiFe-MOFs but also markedly boost their visible-light photocatalytic activity. The optimized membranes (TFN-NC3) achieve an exceptional pure water permeance of 20.2 LMH/bar (L m −2  h −1  bar −1 )—approximately 2.3 times that of conventional thin-film composite (TFC) membranes—while maintaining a high Na 2 SO 4 rejection of 98.2% and outstanding removal rates (>86%) for multiple dyes across a range of molecular weights and charges. Moreover, the membranes demonstrate robust tetracycline rejection (>93.4%) over a broad pH range. Under visible-light irradiation, the TFN-NC3 membranes exhibit remarkable self-cleaning capability, sustaining a flux recovery rate above 95% over five consecutive filtration-regeneration cycles. This work provides a facile and scalable approach to fabricate high-performance, fouling-resistant nanofiltration membranes, offering a promising solution for the sustainable treatment and reuse of dye-laden wastewater.