Scientists at Kiel University in Germany have scaled up a porous material that can pull nearly two liters of drinking water per kilogram from the air each day — even in bone-dry desert conditions — and say it is now ready for industrial production.
The material, known as CAU-10-H, belongs to a class of compounds called Metal-Organic Frameworks, or MOFs. These crystalline structures are riddled with microscopic pores that act like molecular sponges, soaking up water vapor and releasing it again on demand. The foundational chemistry behind MOFs earned researcher Omar Yaghi the 2025 Nobel Prize in Chemistry, and the technology is now attracting serious commercial interest around the world.
What makes CAU-10-H particularly exciting is how little moisture it needs to work. Most water-harvesting materials require relatively humid conditions to function. CAU-10-H begins capturing water molecules once relative humidity passes just 18 percent — conditions most systems would dismiss as too dry to bother with. This makes it useful in some of the world's most water-stressed environments, from the drying Mediterranean coast to the Sahara and beyond.
"Regions like these are facing rising temperatures and declining rainfall," said Professor Norbert Stock, the lead author of the research at Kiel University's Institute of Inorganic Chemistry. "Our goal is to develop an environmentally friendly technology that converts water molecules from the air into drinking water."
Releasing the captured water requires no expensive industrial equipment. Heating the material to just 70 degrees Celsius is enough — a temperature easily reached using solar energy or waste heat from a nearby factory. Combined with carbon-based conductive structures that accelerate the absorption and release cycle, the Kiel team achieved continuous operation with each cycle lasting just a few hours.
Under test conditions, CAU-10-H captures 0.17 grams of water per gram of material. Scaled up, that translates to a projected yield of around 1.8 liters of water per kilogram of the composite per day. "This makes the material particularly attractive for producing drinking water, even in arid regions," said Lasse Wegner, one of the study's co-authors.
The material also doubles as an unusually efficient refrigerant. In cooling systems powered by waste heat, CAU-10-H performs three times better than silica gel, the desiccant most commonly used in industrial applications today. This means it could help data centres, bakeries, and other heat-generating facilities cool themselves without adding to their electrical load.
Most crucially, the researchers have now demonstrated that CAU-10-H can be manufactured at scale. With backing from Kiel University's validation fund, the team produced around 30 kilograms of the material — roughly 60 times more than any previous lab batch — at an estimated cost of $12 to $14 per kilogram. "We have shown that they not only work in the laboratory but can also be produced on an economically viable scale," Professor Stock said.
The research was published in two peer-reviewed journals: the Journal of Materials Chemistry A and Industrial and Engineering Chemistry Research. The team now hopes to attract commercial partners to bring the technology to the communities that need it most — places where clean water is increasingly scarce, and where the air itself may be the only source worth tapping.
