Ambient-Dried MOF/Cellulose-Based Aerogels for Atmospheric Water Harvesting and Sustainable Water Management in Agriculture

Atmospheric water harvesting (AWH) is a promising approach to address water scarcity; however, achieving scalable and efficient materials remains a critical challenge. Herein, we present ambient-dried aerogels composed of biobased materials (cellulose nanofibers and sodium alginate), integrated with metal–organic frameworks (MOFs) and hygroscopic salts for effective AWH. A key innovation in this system is the functional incorporation of MOFs into the aerogel scaffolds, where they enhance water capture at low relative humidity (RH) and contribute to improved salt stabilization. The biobased matrix facilitates ambient drying, while promoting efficient water transport and absorption. The prepared aerogels demonstrate a competitive water uptake of 0.32 g/g at 25% RH and 3.52 g/g at 90% RH within 12 h. When coated with a carbon nanotube (CNT) layer, the aerogels achieve a solar-driven evaporation efficiency of ≈70%. As proof of concept, the aerogels were used to create microclimates inside a terrarium, where atmospheric water absorbed by the system was released under solar irradiation to sustain a plant growth for two weeks. This stategy can be extended to greenhouses, leveraging high humidity and waste heat for enhanced water regeneration, alongside ventilation systems to optimize water collection efficiency, representing a transformative opportunity for sustainable agriculture.