Tillandsia‐Inspired Ultra‐Efficient Thermo‐Responsive Hygroscopic Nanofibers for Solar‐Driven Atmospheric Water Harvesting

Abstract Sorption‐based atmospheric water harvesting (SAWH) is a promising approach for supplying water in off‐grid arid regions. However, it is difficult to improve the SAWH efficiency because water undergoes multiple phase transformations, such as water vapor–water (desorption and condensation) in the desorption phase. To address this issue, an ultrahygroscopic temperature‐responsive hydrogel nanofiber inspired by Tillandsia is developed, comprising poly N‐isopropylacrylamide, poly N‐dimethylacetamide, and carbon nanotubes and impregnated with lithium chloride (PCP@LiCl). The hydrophobicity of the nanofiber membrane is enhanced with increasing temperature, facilitating water separation from the hydrogel in liquid form. Moreover, PCP@LiCl exhibits unique kinetics at 25 °C and 15%–30% relative humidity, capable of adsorbing moisture to saturation within 2 h, and oozing liquid water within 5 min under sunlight. Through global potential modeling, it is demonstrated that PCP@LiCl has potential applications in arid and semiarid regions. This study provides new insights into the design of high‐performance composites for solar‐powered atmospheric water harvesting.