Hygroscopic LiCl@MOF‐Grafted Fibrous Mats for Scalable Solar‐Powered Atmospheric Water Harvesting

Solar-induced sorption-desorption based atmospheric water harvesting (SSDAWH) has emerged as a promising technology to mitigate global water scarcity through moisture capture across broad relative humidity (RH) ranges using advanced sorbents. While metal-organic frameworks (MOFs) have demonstrated exceptional potential in water capture applications, their practical implementation faces two critical challenges: the persistent gap between laboratory research and field deployment, and sluggish desorption kinetics that severely constrain SSDAWH system efficiency. To address these limitations, a novel MOF-303-LiCl composite integrated with reactive black dye-grafted fibrous mats (LiCl@MOF-chelated black viscose nonwoven mat, LMBVNM) is developed, creating a photothermal sorbent platform that enables rapid and complete moisture cycling. This engineered architecture achieves dual functionality: the fibrous mats substrate provides mechanical stability and mass transport channels for practical device integration, while the MOF-303-LiCl/dye system synergistically enhances both moisture capture capacity and solar-driven release kinetics. The system demonstrates exceptional performance with a record adsorption capacity of 4.95 g_water·g_adsorbent ^-1 at 90% RH combined with 98.2% water recovery within 20 min under 1 sun illumination. Although MOF-303 is well-known in the materials community, the innovation lies in incorporating MOF-303 into reactive black dye-grafted commercial fibrous mats, paves the way for the large-scale practical application of MOFs in atmospheric water harvesting.