A novel homogeneous amphipathic PTFE/β-FeOOH nanofiber membrane for emulsion separation and photocatalytic degradation in harsh environments

The efficient separation of emulsion and the simultaneous degradation of organic pollutants remain critical challenges in wastewater treatment, particularly under harsh environments. In this work, a multifunctional Polytetrafluoroethylene (PTFE)/β-FeOOH (beta-iron oxyhydroxide) nanofiber membrane was successfully fabricated via electrospinning combined with in situ mineralization. The membrane exhibited superamphiphilicity in air, underwater superoleophobicity, and superhydrophobicity in oil, with tunable surface wettability. Uniformly anchored β-FeOOH nanorods increased surface roughness and hydrophilicity while providing abundant catalytic sites, enabling synergistic oil–water emulsion separation and photo-Fenton degradation. At a low operating pressure of 0.2 bar, high permeation fluxes of 2713.29 and 2108.37 L·m -2 ·h -1 were achieved for O/W and W/O emulsions, with separation efficiencies up to 99.90 %. The membrane maintained excellent chemical stability after 10 separation–regeneration cycles under pH 1 and 30 wt.% NaOH conditions, retaining fluxes of 1948.47 and 2150.53 L·m -2 ·h -1 with efficiencies of 99.38 % and 99.62 %, respectively. Additionally, methylene blue and rhodamine B removal rates remained above 98 % after five photo-Fenton cycles, and the flux recovery rate reached 97.88 %. These results demonstrate superior chemical resistance, antifouling properties, and long-term durability. Therefore, the proposed PTFE/β-FeOOH nanofiber membrane offers a promising strategy for efficient emulsion separation and organic pollutant purification in harsh environments.