LAUSR

Sorbent-based atmospheric water harvesting (AWH) has emerged as a promising decentralized water production technology to mitigate the freshwater crisis in arid areas. Hydrogels have been regarded as attractive sorbents due to their high water retention and tailorable polymer-water interactions. Yet, the kinetics of water sorption and desorption at low relative humidity (RH) should be improved for their practical implementation. Here, we report hygroscopic microgels (HMGs) composed of hydroxypropyl cellulose (HPC) and hygroscopic salt, achieving a water uptake of ac. 0.5-0.8 g g-1 at 15-30% RH. HMGs enable rapid sorption-desorption kinetics owing to the short-distance diffusion in microgels and hydrophilicity-hydrophobicity switching of thermoresponsive HPC. To validate the feasibility of HMGs for moisture extraction, a potential daily water collection of up to equivalent 7.9 to 19.1 L kg-1 at low RH was demonstrated enabled by 24-36 operation cycles per day based on the material-level experiments. With renewable raw materials and superior performance, HMGs provide a sustainable approach for rapid moisture extraction in arid climates. This article is protected by copyright. All rights reserved.