Shrinkage‐Resistant Thermo‐Responsive Hygroscopic Hydrogel Toward Ultra‐Rapid Cycling Atmospheric Water Harvesting

Abstract Freshwater scarcity presents a significant threat to socio‐economic development, particularly in agriculture and light industry in remote and underdeveloped regions. Sorption‐based atmospheric water harvesting (SAWH) offers a promising solution, yet the primary challenge remains the efficient and continuous extraction of clean water from air. Here, a supramolecular design strategy is proposed to synthesize shrinkage‐resistant thermos‐responsive hydrogel (PCC20@LiCl) that demonstrates rapid thermal response, stable phase‐transition size, and effective lithium chloride (LiCl) entrapment. The hydrogel achieves high water sorption capacities of 0.99 ± 0.03 and 5.43 ± 0.37 at 20% and 80% relative humidity, respectively, along with a rapid solar‐driven water release rate. Additionally, this study demonstrates a solar‐powered, rapid‐cycling SAWH device that reuses desorption heat to maximize sorbent efficiency. By alternately switching between sorption and desorption chambers, the device completes nine consecutive cycles per day, achieving a water collection rate of 1,417 and 1,134.4 . This work demonstrates the potential to meet domestic and irrigation water demands, advancing SAWH technology for practical implementation in economically underdeveloped regions.