Solar‐Driven Sorption‐Based Atmospheric Water Harvesting With a Circadian Synergy for Arid Regions

ABSTRACT

Solar‐driven sorption‐based atmospheric water harvesting has emerged as a transformative strategy to address water scarcity in arid and landlocked regions worldwide. Unlike conventional water production methods that rely on liquid water sources, this approach exploits the ubiquity of atmospheric moisture and the renewability of solar energy to deliver freshwater where it is most needed. Central to this technology is the design of advanced hygroscopic materials that integrate three essential functions: efficient water vapor capture under low humidity conditions, photothermal conversion for solar heating, and stimuli‐responsive water release with minimal energy penalty. This review examines the fundamental mechanisms and performance of water sorption across diverse material systems, ranging from hygroscopic salt composites and metal‐organic frameworks to functional polymer gels and hierarchically porous Fibers. Particular emphasis is placed on the circadian operational synergy that aligns nocturnal water adsorption with diurnal solar‐driven desorption, a principle inspired by natural organisms. Beyond water production, the integration of atmospheric water harvesting with photocatalytic hydrogen generation is considered as an emerging direction for distributed energy‐water nexus applications. Finally, we offer an outlook on the future development of this field, providing an efficient pathway for the continued advancement of high‐performance atmospheric water harvesting technologies suitable for arid environments.