Hierarchical TiO2 Nanorod Arrays/Carbon Nanofiber Membranes for Oil-in-Water Emulsion Separation

Although much attention has been paid to efficient treatment of oily wastewater, it is still a tough challenge to treat oil-in-water emulsions with tiny oil droplets. In this work, hierarchical TiO2 nanorod arrays/carbon nanofiber composite membranes with multilevel pore structure, attractive superhydrophilicity, and underwater superoleophobicity are fabricated for oil-in-water emulsion separation by a facile electrospinning method followed by hydrothermal synthesis. These membranes exhibit an efficient oil-in-water emulsion separation performance with a separation efficiency above 99% and a high separation flux of 1108.8 L m–2 h–1. Interestingly, by inducing hydroxyl groups on TiO2 via UV irradiation, the separation performance is improved further because of the improved hydrophilicity. Simultaneously, benefiting from the excellent chemical stability of the rutile-phase TiO2, the composite membrane shows outstanding corrosion resistance, high temperature resistance, and good recyclability. The composite membrane has a promising prospect in the field of oil-in-water emulsion separation and resource recovery.