Radiative cooling layer boosting hydrophilic-hydrophobic patterned surface for efficient water harvesting

Water harvesting from fog is of considerable interest as a nominated solution to freshwater shortage in arid and underdeveloped regions. The unique hydrophilic and hydrophobic patterns on the dorsal surface of the Namib Desert Beetle have been shown to be an evolving and effective strategy for harvesting water from air. Illuminated by the Namib desert beetle, different elaborate patterns based on aluminum plates were established and their water harvesting efficiency was investigated from a comparative perspective. The results showed that the veinlike patterned surfaces had the highest (786.15 mg circle cm(-2) h(-1)) water collection efficiency. However, the heat released during the condensation process affected the water collection rate. In order to reduce the re-evaporation rate of water droplets, a radiant cooling layer was designed on the other side of the water collection plate to release the condensation heat. The radiation cooling layer employed MgHPO4 center dot 0.78 H2O as the functional particle and P(VDF-HFP) as the adhesive. Benefitted from radiative cooling layer, the water collection efficiency could be increased by 198.51 mg circle cm(-2) h (-1). The water collection material with double-sided function structure has low preparation costs and green raw materials. This work provides an effective way to develop key materials with freshwater harvesting capabilities.

Automated summary

Water harvesting from fog is a promising solution for freshwater shortage in arid regions. The hydrophilic and hydrophobic patterns on the Namib desert beetle's dorsal surface have inspired the development of aluminum plates with different patterns for water collection. The veinlike patterned surfaces showed the highest water collection efficiency, but the condensation heat affected the collection rate. To reduce re-evaporation, a radiant cooling layer was designed, increasing the water collection efficiency. This work provides a cost-effective and environmentally friendly approach to developing materials for freshwater harvesting.