Biomimetic nanonet membranes with UV-driven self-cleaning performance for water remediation

Water pollution caused by industrial and natural contaminants has placed a significant burden on environment and human health. The present filtration membranes, however, suffer from a series of issues involving low permeation fluxes and easy fouling issue during long-term water remediation, which seriously restricts their practical applications. Herein, inspired by royal water lily leaf, we construct biomimetic nanonet membranes (BNMs) composed of fractal network and mastoid structures by one-step phase inversion of PVDF/TiO2 solution using electrospun fibrous membrane as substrates. Benefit from the distinct structures, the BNMs show sub-micro pores, high porosity, and intriguing hydrophilicity, which result in excellent removal performance for 0.3 & mu;m solid particle (efficiency of 99.88%, permeation flux of 3439 L m- 2 h-1), E. coli (log reduction value = 8.39, permeation flux of 1242 L m- 2 h-1), and oil-in-water emulsions (efficiency of 99.0%, permeation flux of 8312 L m- 2 h-1). Importantly, the presence of TiO2 nanoparticles with UV-driven catalytic activity effectively endows the BNMs with desirable biocidal efficiency (LRV = 8.5) and excellent self-cleaning properties (flux recovery ratio of 98.1%). The synthesis of such membranes may open new avenues in the design of high-performance filtration membranes for remediation of large volumes of wastewater.