A single step fabrication of bio-inspired high efficiency and durable water harvester made of polymer membranes

Inadequate fresh water supply in this planet has created a pressing need for developing a high-performance water harvester. To address this issue, inspired by Namib Desert beetle, an artificial hydrophobic/hydrophilic porous water harvester was successfully fabricated in this work via a facile single step approach of electrospinning PVDF/PAN composite solutions. The wetting phenomenon of as-spun bead-free nanofibers was evident that there was formation of novel wettability containing both hydrophobicity and hydrophilicity, and then the water collection test results demonstrated the formation of hydrophobic/hydrophilic membranes could significantly enhance the water harvesting efficiency. Highest water harvesting efficiency of ~315 mg/cm2/h was obtained from PVDF/PAN composite membranes, which was 3 times that of the virgin PVDF in this work. The hydrophobic/hydrophilic phase ratios (by altering the weight ratio of PVDF/PAN) will also decide the wettability of as-spun membranes, eventually affect the water harvesting ability. [Display omitted] •Bio-inspired membranes were fabricated with enhanced water harvesting efficiency.•Electrospinning technology was used to prepare membrane with complex wettability in single step.•PVDF and PAN were chosen to serve as the hydrophobic and hydrophilic part, respectively.•A water harvester efficiency as high as 315 mg/cm2/h was achieved.