A quadruple biomimetic hydrophilic/hydrophobic Janus composite material integrating Cu(OH)2 micro-needles and embedded bead-on-string nanofiber membrane for efficient fog harvesting

Bioinspired by the cactus spines, desert beetle, spider silk and the lotus leaf, we designed a hydrophilic/hydrophobic Janus NF/MN material integrating with Cu(OH)2 micro-needles and embedded PVC bead-on-string nanofibers. The material with high specific surface area enhanced the droplet capture, deposition and transport. Results revealed that the Janus NF/MN material could reduce the secondary water evaporation with a water retention of 92.97% and show the best fog-harvesting efficiency with 80.57 mg·min−1·cm−2.