Solar‐Driven Drum‐Type Atmospheric Water Harvester Based on Bio‐Based Gels with Fast Adsorption/Desorption Kinetics

• Published in: Advanced materials (Weinheim) Vol. 36; no. 32; pp. e2403876 - n/a
• Main Authors: Zhou, Hao, Yan, Li, Tang, Dexi, Xu, Ting, Dai, Lin, Li, Chenyu, Chen, Wenshuai, Si, Chuanling
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.08.2024
• Subjects: adsorbing gel; Adsorption; Alginates; atmospheric water harvesting; biomass; Desorption; Drinking water; Extreme environments; Gels; Kinetics; lignin; Lithium chloride; Photothermal conversion; Portability; Relative humidity; sodium alginate; Water yield; adsorbing gel; sodium alginate; atmospheric water harvesting; biomass; lignin
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202403876

Sorption‐based atmospheric water harvesting is an attractive technology for exploiting unconventional water sources. A critical challenge is how to facilitate fast and continuous collection of potable water from air. Here, a bio‐based gel (cellulose/alginate/lignin gel, CAL gel), resulting from the integration of a whole biomass‐derived polymer network with lithium chloride is reported. A fast adsorption/desorption kinetics, with a water capture rate of 1.74 kg kg−1 h−1 at 30% relative humidity and a desorption rate of 1.98 kg kg−1 h−1, is simultaneously realized in one piece of CAL gel, because of its strong hygroscopicity, hydrophilic network, abundant water transport channels, photothermal conversion ability, and ≈200‐µm‐thick self‐supporting bulky structure caused by multicomponent synergy. A solar‐driven, drum‐type, tunable, and portable harvester is designed that can harvest atmospheric water within a brief time. Under outdoor conditions, the harvester with CAL gels operates 36 switches (180°) per day realizes a water yield of 8.96 kg kggel−1 (18.87 g kgdevice−1). This portable harvester highlights the potential for fast and scalable atmospheric water harvesting in extreme environments. A solar‐driven, fast moisture adsorbing and desorbing gel (cellulose/alginate/lignin gel) exhibits a water capture rate of 1.74 kg kg−1 h−1 (at 30% relative humidity) and a desorption rate of 1.98 kg kg−1 h−1. The switching frequency of the developed drum‐type harvester can be flexibly optimized to achieve the highest efficiency of atmospheric water harvesting within a brief time.