Self-Cleaning Nanofiltration Membranes by Coordinated Regulation of Carbon Quantum Dots and Polydopamine

Performance declination of nanofiltration (NF) membranes caused by concentration polarization (CP) and membrane fouling has severely restricted their practical application in many fields. This work reports the construction of a novel interlayer between the substrate and the selective layer of conventional composite membranes by coordinating regulation of carbon quantum dots (CQDs) and polydopamine (PDA). Unlike traditional methods that treat CP and fouling separately, the new strategy grants the membrane with dual functions at one time. First, the insertion of the PDA–CQDs layer reformulates the interfacial polymerization process that reduces the solute transport resistance and mitigates the CP issue. Second, the sandwiched photoactive CQDs can degrade organic molecules adsorbed on the membrane surface under visible light, which is promising for low-cost fouling remediation. This study may offer valuable insights into the preparation of durable self-cleaning NF membranes for the effective treatment of complex wastewater in various industries.