Highly efficient sunlight-driven self-cleaning electrospun nanofiber membrane NM88B@HPAN for water treatment

Electrospun membranes show great potential as separation materials for water purification due to their high porosity and three-dimension (3D) configuration. However, membrane fouling has still not been effectively solved. In this work, hydrophilic and visible-light responsive NM88B@HPAN nanofiber membrane was fabricated, via introduced the catalyst of NH2-MIL-88B(Fe) (NM88B) into the 3D matrix of the hydrolyzed polyacrylonitrile (HPAN) membrane. Owning to the partial dissociation of protons in carboxyl functional groups, the surface of HPAN membrane shows a negative charge in water, which is conducive to improve the interaction between HPAN membrane and protonated NM88B, resulting in good dispersion of nanoparticles on the membrane surface and high stability of NM88B@HPAN nanofiber membrane. The nanofiber membrane exhibited excellent separation efficiency (up to 99%) and high permeation flux (946-6014 L/m(2)/h) towards various oil/ water emulsions. Meanwhile, the membrane has high flux recovery rate and dye degradation ability towards Rhodamine B (RhB) (90.04%) owing to the synergistic effect of strong hydrophilicity and photo-Fenton activity. Moreover, good mechanical property was observed of the composite nanofiber membrane, which was beneficial for repeated use in the actual production process.

Automated summary

Electrospun membranes have potential as separation materials for water purification, but membrane fouling remains a challenge. In this study, a hydrophilic and visible-light responsive nanofiber membrane was fabricated, showing excellent separation efficiency and high permeation flux. The membrane also demonstrated high dye degradation ability and flux recovery rate, along with good mechanical properties.