Photo-Fenton self-cleaning membranes with robust flux recovery for an efficient oil/water emulsion separation

Abstract

Superhydrophilic/underwater superoleophobic membranes have aroused much research enthusiasm because of their good anti-fouling ability for the treatment of oil-contaminated water. However, such anti-fouling membranes inevitably suffer from fouling during long-term use. Thus, anti-fouling membranes with excellent self-cleaning performance, fast and superior flux recovery are still greatly required. Herein, the green tannic acid (TA)-Fe(III) complex is first assembled onto the polyvinylidene fluoride membrane (PVDF) surface and followed by the in situ mineralization of β-FeOOH to fabricate the PVDF/TA/β-FeOOH membrane for efficient oil/water emulsion separation. The resultant membrane exhibits superhydrophilicity and underwater superoleophobicity with underwater OCA of above 155° for various oils. Importantly, the as-prepared membrane shows fast (within 10 min) and excellent flux recovery (over 98%) attributed to the robust photo-Fenton catalytic activity of β-FeOOH. Moreover, the membrane also displays high separation efficiency (>99.1%) and high flux (1426.8–2106.2 L m⁻² h⁻¹ bar⁻¹) for a series of oil/water emulsions. This study highlights a new direction in the development of photo-Fenton self-cleaning membranes with fast and robust flux recovery for efficient oil/water emulsion separation.