A General In Situ Strategy to Fabricate Photocatalytic Self-Cleaning Membranes with QDs-Decorated COFs

Covalent triazine frameworks (CTFs), a subclass of covalent organic frameworks (COFs) based on triazine units, possess a high specific surface area and excellent optoelectronic properties, making them highly suitable for constructing photocatalytic nanocomposites. In this study, a high-performance photocatalytic self-cleaning membrane was developed by incorporating WS2 quantum dot-decorated CTF-A (WS2 QDS@CTF-A) into a polyvinylidene fluoride (PVDF) matrix. The composite membrane effectively synergized the excellent optoelectronic properties of CTF-A with the strong photocatalytic activity of WS2 QDs. Under simulated sunlight, the membrane efficiently generated •OH/•O2– radicals, which drove the degradation of adsorbed dye molecules, thereby endowing it with remarkable self-cleaning and antifouling properties. The optimized membrane (QL2) exhibited superior separation performance, achieving a pure water flux of 28.27 L·m–2·h–1·bar–1 and a rejection rate exceeding 99% for Eriochrome Black T. Notably, the photocatalytic functionality ensured excellent reusability, enabling the membrane to maintain over 90% separation efficiency throughout eight filtration cycles, which underscores its potential for sustainable wastewater treatment.