New MOF captures water from air in ultra-dry conditions

By AI, Created 10:35 AM UTC, May 21, 2026, /AGP/ – Researchers in China developed a gallate-based metal-organic framework that pulls water from air at just 0.2% relative humidity, a level so dry that most adsorbents fail. The magnesium version could help with water scarcity in deserts and other low-moisture settings, while also pointing to uses in dehumidification and industrial drying.

Why it matters: - Atmospheric water harvesting could give water-stressed regions a new source of supply where conventional systems do not work well. - The new material is designed to function at ultra-low humidity, opening a path for use in deserts, dry industrial settings, and other extreme environments. - The same technology could also support semiconductor dehumidification, electronics protection, natural gas dehydration, and space-based water recovery systems.

What happened: - Researchers at Henan Normal University developed a gallate-based metal-organic framework, or MOF, that can harvest water directly from air in extremely dry conditions. - The strongest performer in the group was magnesium-based Mg-gallate. - Mg-gallate captured 170 mg of water per gram at 0.2% relative humidity. - The work was led by Professor Jianji Wang and Professor Huiyong Wang, with co-authors Rui Zhou, Xueli Ma, Yunlei Shi, Wei Lu, Dazhen Xiong, and Zhiyong Li. - The study was published in Green Chemical Engineering. - The full article is available here.

The details: - The MOF was built from low-cost materials including magnesium, cobalt, and nickel. - Mg-gallate showed strong water adsorption capacity and high structural stability. - The material remained structurally stable after 28 days in water. - Mg-gallate kept strong performance after 20 adsorption-desorption cycles. - The MOF showed high selectivity for water molecules over nitrogen. - The material was produced on a gram scale using inexpensive raw materials and standard laboratory methods. - The performance comes from hydrogen-bonding interactions between water molecules and oxygen-containing groups inside the MOF structure. - Ultramicroporous channel filling effects also contribute to the water uptake.

Between the lines: - The result matters because many current water-harvesting materials lose effectiveness when humidity drops very low. - A stable, low-cost material that works at record-low humidity could make atmospheric water harvesting more practical beyond lab settings. - The gram-scale synthesis is important because large-scale production is often a barrier for advanced porous materials.

What’s next: - The research team sees the MOF strategy as a route toward practical water-harvesting systems for some of the driest places on Earth. - Further work will likely focus on scaling production and testing the material in real-world devices and harsh environments. - Broader applications may emerge in drying, purification, and water recovery systems if the material continues to perform outside the lab.

The bottom line: - Mg-gallate combines ultra-dry air capture, stability, and low-cost synthesis in one material, making it a promising candidate for next-generation atmospheric water harvesting.