An Autonomous Passive MOF Water Harvester for Extreme Arabian Desert Conditions

Here we report an off-grid, passively heated, sorbent-assisted atmospheric water harvesting device. A metal–organic framework, Al(μ 2 -OH)[( E )-5-(2-carboxyvinyl)furan-2-carboxylate], is integrated as thin coatings in a disc-stack architecture to enhance moisture transport and heat transfer. Under laboratory conditions, the device harvested 660 mL kg MOF −1 day −1 and recovered 175 mL of water across two cycles in an 11.5 h simulated day, demonstrating uniquely fully autonomous multicyclic operation in a passively heated water harvester. Field tests near Al-Muzahmiyya (24.3416° N, 46.0203° E) in the Arabian Desert of Saudi Arabia, performed under frequent sandstorms and extremely challenging conditions for water harvesting (RH avg = 12.4 %, T avg = 20.5 °C), including dust-attenuated solar irradiance (I avg = 496 W m −2 ) produced 46.7 ± 1.5 mL day −1 (185 mL kg MOF −1 day −1 ). These results demonstrate the highest reported specific productivity for a passively heated water harvester under very low humidity (RH avg < 20%) desert operation and represent the most severe reported field deployment conditions for any water harvester.