Multi-scaled, hierarchical nanofibrous membrane for oil/water separation and photocatalysis: Preparation, characterization and properties evaluation

Increasing oily wastewater is produced by various industrial, various oil-water separation technologies and materials have been developed to solve this issue. A facile method is proposed to build multi-scaled and hierarchical membranes with efficiently oil/water separation and photocatalysis. The multi-scaled, hierarchical membrane is fabricated by a hydrophilic polyacrylonitrile (PAN) electrospinning nanofibrous and PAN/TiO2 electrospraying spheres, then the polydopamine (PDA) decorated membrane via in-situ growth. This multi-scaled, hierarchical structure endows the membrane with superhydrophilicity (water contact angle ∼ 0°), and underwater superoleophobicity (oil contact angle ∼152°). And the multi-scaled, hierarchical membrane shows superior water permeation and hydrophilic properties than pure PAN membranes. In addition, the membrane indicates an excellent photocatalytic ability for organic pollutant (∼98 %). And after 5 cycles, the water flux still maintains a high level showing good recyclability. This multi-scaled, hierarchical nanofibrous membrane shows very promising application potentials in oil-water separation and photocatalysis.