These molecular sponges that can capture CO2 and purify water

Introduction: the discovery that earned the 2025 Nobel Prize in Chemistry

Materials capable of trapping invisible molecules

Imagine a material so porous that a single gram could, in theory, unfold an internal surface as large as several sports fields. That is exactly the principle behind metal-organic frameworks, better known by their acronym MOF, materials that earned the 2025 Nobel Prize in Chemistry for three researchers for their foundational discovery in this field, a discovery many chemists now describe as one of the most versatile of the past half-century.

These crystalline architectures, somewhere between a molecular construction set and a microscopic sponge, are able to selectively capture certain molecules, whether polluting gases, carbon dioxide, or even water vapor present in the driest air. There is something fascinating about imagining a material capable of choosing, almost like sorting at the atomic scale, which molecules it wants to retain.

Three researchers honored for a foundational discovery

The 2025 Nobel Prize in Chemistry was awarded to Susumu Kitagawa, Richard Robson, and Omar Yaghi, three scientists whose work, carried out over several decades, made it possible to design and refine these metal-organic frameworks. Their research transformed a laboratory curiosity into an entire family of materials with potentially enormous applications for green chemistry in the twenty-first century.

This international recognition underscores the considerable importance the scientific community places on these materials, capable of addressing major environmental challenges, from carbon storage to producing drinking water in the most arid regions of the globe.

How a metal-organic framework works

An architecture built like a molecular construction kit

MOFs are made of metal ions linked together by organic molecules, forming a three-dimensional crystalline structure pierced with regular pores, somewhat like an enormous microscopic scaffold. This architecture can be adjusted with remarkable precision by changing the nature of the components used, which makes it possible to manufacture thousands of different variants, each tailored to a specific application.

This modularity is one of the great strengths of these materials: simply by changing the size or shape of the pores, or the chemical nature of the internal surfaces, researchers can design structures capable of very specifically capturing a given molecule, while letting others pass through.

An internal volume far exceeding that of the solid material

One of the most spectacular properties of these metal-organic structures lies in their extreme porosity. The internal volume available for capturing molecules can exceed a hundred times that of the solid material itself, which explains why a relatively modest amount of MOF can absorb an impressive quantity of gas or liquid, sometimes enough to fill what looks, from the outside, like an impossibly small container.

This exceptional absorption capacity is reminiscent, on a very different scale, of the principle of an ordinary sponge, but at a far finer microscopic scale and with much greater chemical selectivity, capable of distinguishing between molecules with very similar properties.

Capturing CO2 to fight climate change

A concrete response to a major environmental challenge

One of the most promising applications of metal-organic frameworks concerns carbon dioxide capture, a central issue in the fight against climate change. Some MOFs are specifically designed to selectively trap CO2 molecules present in ambient air or in industrial flue gases, before they are released into the atmosphere.

This technology could eventually be integrated directly into factory or power plant smokestacks, capturing CO2 at the source, before it even has the chance to contribute to global warming. Other approaches even envision direct capture of CO2 already present in the atmosphere.

A potential that appeals to industry and researchers alike

Several companies and research laboratories around the world are actively exploring the integration of these materials into industrial carbon capture devices. The chemical flexibility of MOFs makes it possible to envision solutions tailored to very different industrial contexts, whether steelmaking, cement production, or electricity generation from fossil fuels.

While many of these applications remain at the industrial development stage, they illustrate the considerable potential of this family of materials in supporting the transition toward a less greenhouse-gas-intensive economy.

Producing drinking water from desert air

An almost magical feat in the most arid regions

Beyond carbon capture, certain metal-organic structures have a remarkable ability to capture water molecules present in the air, even in extremely dry environments such as deserts. This property opens up the possibility of designing devices capable of producing drinking water directly from atmospheric humidity, without requiring any pre-existing liquid water source.

This type of application could have a considerable impact in regions of the world suffering from limited access to drinking water, offering a complementary supply source, particularly valuable in areas where traditional water infrastructure is absent or insufficient.

Devices already tested in the field

Prototype atmospheric water harvesters using MOFs have already been tested under real desert conditions, demonstrating these materials' ability to extract a significant amount of water even at very low humidity levels. These experiments, though still limited in scale, constitute an encouraging proof of concept for future larger-scale applications. Early field trials have reportedly produced several liters of usable water per day from units no larger than a household appliance, a modest but meaningful start.

This technology perfectly illustrates how a fundamental chemistry discovery can lead, after years of development, to concrete solutions for urgent human problems, such as access to drinking water in the most arid regions of the planet. Researchers working on these prototypes often stress that scaling them up remains the hardest part, since a device that performs well in a controlled test still needs to survive years of dust, heat, and unpredictable weather in the real world.

An advance described as essential for green chemistry

A recognition that also rewards scientific patience

It's worth remembering that the first work leading to this discovery dates back several decades, well before the general public took any interest in these materials. Richard Robson laid the first conceptual groundwork as early as the late 1980s, a period when the very idea of designing custom porous crystals still seemed relatively marginal within the chemistry community, pursued by only a handful of laboratories willing to bet on such an unconventional line of research.

There is something admirable about this kind of scientific tenacity, that of researchers who pursue an idea for decades before the whole world finally recognizes its true significance.

Susumu Kitagawa and Omar Yaghi then considerably expanded and systematized this approach in the following years, turning an initial insight into a full-fledged scientific discipline, now taught at the world's leading chemistry universities.

A material with applications that go beyond water and carbon

Metal-organic frameworks are not limited to CO2 capture or water production. Researchers are also exploring their use for hydrogen storage, purifying industrial pollutants, or catalyzing chemical reactions that require very fine molecular selectivity. This versatility largely explains the enthusiasm this discovery has generated within the scientific community, with new proposed uses appearing in academic journals almost every month.

This diversity of potential applications makes MOFs particularly valuable in today's context of transitioning toward green chemistry, where the ability to design custom, efficient, and adaptable materials becomes a major asset for addressing the environmental challenges of the twenty-first century.

The industrial challenges that remain to be overcome

Despite this enthusiasm, several challenges remain before these materials can be adopted on a massive industrial scale. Their production cost remains relatively high compared to more conventional solutions, and their long-term stability under real industrial conditions still needs to be fully demonstrated over extended periods of use, particularly when exposed to repeated cycles of humidity, heat, and mechanical stress.

Researchers therefore continue working to optimize the manufacturing processes for these materials, hoping to reduce their costs and improve their robustness, two conditions essential to enabling large-scale deployment of these promising technologies.

How to recognize a MOF in upcoming innovations

Concrete clues for spotting this technology

For the general public, it is not always easy to tell when an innovation relies on metal-organic frameworks. In general, these materials hide behind technical terms like selective capture, advanced porous material, or molecular sieve, expressions that frequently appear in press releases from technology companies working on environmental issues. Reading between the lines of such announcements can often reveal a MOF at work, even when the acronym itself is never mentioned.

The sectors most likely to adopt this technology in the coming years include low-energy air conditioning, indoor air purification, and industrial gas storage, three fields where the molecular selectivity of MOFs offers a decisive advantage over the more conventional porous materials used until now.

A still-young technology, but poised for rapid adoption

Although discovered decades ago, this family of materials has only truly exploded in the number of known variants over the past fifteen years or so, driven by combined advances in computational chemistry and atomic-scale experimental characterization. Today, tens of thousands of metal-organic structures are catalogued in international scientific databases, and that number keeps climbing as more research groups gain access to the computing power needed to design new variants virtually before ever synthesizing them in a lab.

What strikes me most about this story is the slowness followed by the sudden acceleration of a fundamental discovery that took decades to find its cruising speed before becoming, today, one of the most dynamic fields in materials chemistry.

This recent acceleration suggests a coming multiplication of commercial applications over the next decade, as industrial manufacturing processes improve and production costs continue to gradually decrease.

Conclusion: well-deserved recognition for a chemistry of possibility

What this Nobel Prize reveals about the future of chemistry

The awarding of the 2025 Nobel Prize in Chemistry to Susumu Kitagawa, Richard Robson, and Omar Yaghi crowns decades of patient research into a class of materials that could play a decisive role in addressing today's major environmental challenges. Applications ranging from carbon capture to drinking water production illustrate the considerable scope of this fundamental discovery, a scope that keeps expanding as new laboratories join the effort every year.

This recognition also serves as a reminder of the importance of supporting fundamental research over the long term, since the most transformative applications of a scientific discovery often only become apparent years, or even decades, after its first publication.

Concrete hope for tomorrow's challenges

It is hard not to feel a certain optimism thinking that a material designed at the nanometer scale could eventually help solve problems as vast as climate change or access to drinking water. This dual promise illustrates well how fundamental chemistry can translate into concrete solutions for issues affecting millions of people around the world, from large industrial cities to isolated villages in the most arid regions.

While waiting for wider industrial deployment, these molecular sponges continue to embody one of the most tangible hopes of contemporary green chemistry, carried by scientific recognition now sealed by the Nobel Prize, and by the growing enthusiasm of researchers worldwide who continue exploring this rapidly expanding scientific field.

By Maxime Marquette, columnist

Sources

Primary sources

Nobel Prize — summary of the 2025 Nobel Prize in Chemistry — 2025

Nature — thematic dossier on metal-organic frameworks — 2026

American Chemical Society Publications — associated scientific publications — 2026

Secondary sources

Sciences et Avenir — materials section — 2026

Science et Vie — chemistry section — 2026

Sciencepost — science popularization — 2026