PTFE composite membrane with peroxymonosulfate activation self-cleaning for highly-efficient oil-water emulsion separation and dye degradation

Combining membrane separation with advanced oxidation technology can make the membrane self-cleaning, extending its service life. However, the preparation of composite membranes with excellent catalytic ability, self-cleaning performance, and stability remains a key research direction. In this study, a PTFE composite membrane with peroxymonosulfate activation self-cleaning ability was successfully prepared by in-situ growth of CoOOH and ZIF-67 on the surface of a L-DOPA/PEI modified PTFE membrane. The as-prepared membrane is superhydrophilic and has significant superoleophobic surfaces underwater, the separation efficiency of the as- prepared membrane for multiple oil-water emulsions exceeded 98.4 %. Meanwhile, the effective degradation of several organic dyes under visible light was simulated, with still high degradation efficiency (>99 %) after 10 cycles. Overall, this study puts forward a approach towards self-cleaning membranes based on PTFE material; the resulting composite membrane's high separation efficiency, stability under repeated use conditions as well as its self-cleaning ability position it as an attractive candidate for long-term wastewater purification applications.