Technology

https://www.science.org/doi/full/10.1126/science.aam8743 It really does work better than refrigeration or zeolite based systems.

Here's some of the discussion in the article:

Two-thirds of the world’s population is experiencing water shortages (1). The water in the form of vapor and droplets in the atmosphere, estimated to be about 13 thousand trillion liters (2), is a natural resource that could address the global water problem. Although there has been interest in dewing (3–6) from moist air and fog capture (7–9), these processes require either the frequent presence of 100% relative humidity (RH) or a large amount of energy and thus are not viable solutions for the capture of water from air. Ideally, a water-harvesting system should operate with a material that can take up and release water with minimum energy requirements and that is powered by low-grade energy sources, such as sunlight, in order to potentially allow its deployment in households, especially those located in sunny regions. Here, we demonstrate water harvesting by vapor adsorption using a porous metal-organic framework {microcrystalline powder form of MOF-801, [Zr6O4(OH)4(fumarate)6]} (10) in ambient air with low RH typical of the levels found in most dry regions of the world (down to a RH of 20%). We also report a device based on this MOF that can harvest and deliver water (2.8 liters of water per kilogram of MOF per day at 20% RH) under a nonconcentrated solar flux less than 1 sun (1 kW m–2), requiring no additional power input for producing water at ambient temperature outdoors. Porous materials, such as zeolites, silica gels, and MOFs, can harvest water from air by adsorption over a wide range of humidity values (11–13). However, conventional adsorbents (e.g., zeolites and silica gels) suffer from either low uptake of water or requiring high energy consumption to release water. Although MOFs have already been considered in numerous applications—including gas storage, separation, and catalysis (14–16); heat pumps (17, 18); and dehumidification (19)—the use of MOFs for water harvesting has only recently been proposed (10). The flexibility (20–22) with which MOFs can be made and modified at the molecular level, coupled with their ultrahigh porosity, makes them ideally suited for overcoming the challenges mentioned above.