Fabrication of a PTFE composite membrane with self-cleaning property for high-efficiency oil/water emulsion separation and dye degradation

The development of multifunctional membranes capable of simultaneous oil-water separation and organic pollutant degradation remains a significant challenge. In this study, we investigate a PTFE-based composite membrane modified with l -DOPA tert-butyl ester and PEI hydrophilic coating and functionalized with ZIF-67 and NiOOH, focusing on its surface physicochemical properties, oil-water separation performance, and organic pollutant removal efficiency. The modified membrane activates peroxymonosulfate (PMS) to establish an efficient electron transfer pathway, accelerating the Co/Ni redox cycles and thereby enhancing organic pollutant degradation. The membrane exhibits superior hydrophilicity (reduced water contact angle) and underwater superoleophobicity, achieving a high permeation flux of 361.5 L·m −2 ·h −1 and a separation efficiency exceeding 98.7% under optimized transmembrane pressure. Notably, it maintains a separation efficiency above 98% even after 10 consecutive reuse cycles. Under simulated solar irradiation, the membrane demonstrates exceptional photocatalytic self-cleaning capability, degrading multiple dyes (MB, RhB, MO) with an efficiency of 99.9% within 10 min while maintaining a flux recovery rate of 98.5%. This work presents a robust and sustainable strategy for treating complex oily wastewater through synergistic separation and advanced oxidation processes.