Scientists in the US have identified metal-organic frameworks (MOFs) capable of passively adsorbing almost nine litres of water a day per kilo.
Passive water capture has the potential to impact millions of lives around the world, allowing people to extract water directly from the atmosphere using little or no energy. It can work in arid conditions where other sources of water may not be available and could be a powerful tool for vulnerable communities dealing with the consequences of climate change.
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MOFs are an ideal candidate for passive water capture. Their sponge-like crystal structure gives them the highest surface area per gram of any material. Just one gram of some MOFs would have a surface area of more than an acre if laid flat in a single layer. While some research into using MOFs for water capture has been conducted, this latest work involved an extensive exploration of various MOFs in an effort to find the most adsorbent. The study is published in Scientific Reports.
“Initial experiments have proved that the concept can work,” said co-author Zhiyong Xia, from the Research and Exploratory Development Department at Johns Hopkins’ Applied Physics Laboratory (APL).
“But the problem has been capacity. Other research teams have been able to produce as much as about 1.3 litres of water per day per kilogram of sorbent under arid conditions — enough only for one person. To create an optimal water-harvesting device requires a better understanding of the structure property relationship controlling adsorption and delivery.”

The team tested a number of MOFs and the potential impact of temperature, humidity and powder bed thickness on the adsorption-desorption process. Alongside colleagues Matthew Logan and Spencer Langevin, Xia identified a compound called Zr-MOF-808 that significantly outperformed previous MOFs.
“We identified a MOF that could produce 8.66 litres of water per day per kilogram of MOF under ideal conditions, an extraordinary finding,” he said. “This will help us deepen our understanding of these materials and guide the discovery of next-generation water-harvesting methods.”
The Johns Hopkins team is now exploring other MOFs with low relative humidity influx points, high surface areas and polar functional properties to see how they perform in arid environments. It is also researching different configurations of MOFs in pursuit of optimal adsorption levels.
What volume would 1Kg of this occupy?
Sounds wonderful – but is it scalable? And if so, what are the plans to commercialise it? Also is the water obtained clean and free from contaminants – e.g. from the MOF itself?
Just the technology needed on Arrakis … 🙂
It would have been good to have some more general detail about the breakthrough. How big a volume does the 1kg of MOF take up when it is operational? Is it the size of a domestic fridge freezer, a room, a house, what?
If a passive process is possible it would have fantastic potential to change the lives of all who live in arid, water scarce communities.
Can we have some more information please?
LOL and LOL!! it cannot work in arid conditions, because if the water is not in the air, where can it come from? Indigenous peoples have been hanging grasses above troughs on mountain sides for thousands of years to catch the moisture and condense it. There have also been many gofundme’s based on various forms of “device” claiming to do exactly the same thing, all were scams, most were forms of dehumidifiers that could not possibly be effective given the energy input they were claiming. Once again LOL!
Does this technology remove estrogenic chemicals?
Trevor
Just the technology needed on Arrakis…
We’re all duned…