Civilizations often define their eras by significant materials. We speak of the Stone Age and the Bronze Age, and currently, we reside in the Silicon Age—marked by the prevalence of computers and mobile devices. What might the next defining era be? Omar Yagi from the University of California, Berkeley, posits that the innovative material he pioneered in the 1990s has promising potential: Metal-Organic Frameworks (MOFs). His groundbreaking work in this area made him a co-recipient of the 2025 Nobel Prize in Chemistry.

MOFs, along with their covalent organic frameworks (COFs) counterparts, are crystalline in structure and notable for their exceptional porosity. In 1999, Yagi and his team achieved a milestone by synthesizing a zinc-based structure known as MOF-5. This material is characterized by its numerous pores, boasting an internal surface area equivalent to that of a football field within merely a few grams (refer to the image below). Internally, the structure offers vastly more space than externally.

Over the years, Yagi has been a pioneer in the development of new MOFs and COFs, a field called reticular chemistry. Understanding how these materials can be utilized is a focal point of his research. Their porous nature allows them to absorb other molecules, making them invaluable for applications such as moisture extraction from arid desert air and atmospheric carbon dioxide capture. In an interview with New Scientist, Yagi expressed optimism about this research, discussing the past, present, and future of reticular chemistry and the impending era of these materials.

Karmela Padavic-Callaghan: What inspired your interest in reticular chemistry?

Omar Yagi: Initially, when we began our work with MOFs, we had no concept that we were addressing social issues; it was purely an intellectual pursuit. We aimed to construct materials molecule by molecule, akin to building a structure or programming using Legos. It was a formidable challenge in chemistry. Many doubted its feasibility and considered our efforts futile.

What made the design of materials seem unfeasible?

The primary hurdle in rationalizing material construction lies in the nature of component mixing, which typically results in disordered, complex arrangements. This aligns with physical laws, as nature tends to favor high entropy or disorder. Therefore, our goal was to engineer a crystal—an ordered entity with a recurring pattern.

It’s akin to instructing your children to form a perfect circle in their room—it demands significant effort. Even upon achieving that circle, if you release your hold, it may take too long to re-establish it. We were essentially attempting to crystallize materials in a day—what nature takes billions of years to accomplish. Nonetheless, I believed that with the right knowledge, anything could be crystallized.

In 1999, your intuition was validated with the publication: Synthesis of MOF-5. Did you foresee its potential utility?

We identified a valuable solvent for synthesizing stable MOFs and understanding its mechanism. This critical insight allows us to minimize disorder, effectively tuning the outcome. Subsequently, thousands of researchers have adopted this method.

Initially, I was just elated to create beautiful crystals. Observing their remarkable properties prompted thoughts of potential applications, particularly in trapping gases. Given their internal compartments, these substances can accommodate water, carbon dioxide, or other molecules.

What’s your perspective on creating these materials today?

I usually avoid elaborate cooking and prefer simple, healthy ingredients. This mindset parallels my approach to chemistry: striving for simplicity while utilizing only necessary chemicals. The first step involves selecting the backbone of material; the second, defining pore sizes; the third, administering chemistry on the backbone to incorporate trapping molecules. This process, while appearing simple, is intricately complex.

What pioneering technologies does this process enable?

By mastering molecular-level design, we foresee significant geological transformations. My vision, along with my company founded in 2020, Atco, encompasses progressing from molecules to practical societal applications—addressing material deficiencies in various tasks or enhancing poorly performed tasks with rational designs. Our advancements in material synthesis will elevate societal standards.

Recently, we unveiled COF-999, the most efficient material for capturing carbon dioxide. Undertaking extensive capture tests, we demonstrated its efficacy in collecting CO2 from the atmosphere for over 100 cycles here in Berkeley. Atoco aims to implement reticulated materials like COF-999 in carbon capture modules suitable for both industrial settings and residential buildings.

Additionally, we’ve devised a novel material capable of extracting thousands of liters of water daily from the atmosphere. This technology relies on our device which can pull moisture even in humidities below 20%, such as in desert locations like Nevada. I foresee that within the next decade, water harvesting will emerge as an everyday technology.

How do MOFs and COFs compare with other water and CO2 capture technologies?

We maintain a significant degree of control over the chemistry involved, allowing for sustainable device manufacturing. These devices are long-lasting, and when the MOF component eventually degrades, it can dissolve in water, thus preventing environmental contamination. Consequently, as MOFs scale to multi-ton applications, we should not anticipate a “MOF waste issue.”

For instance, we’ve developed a method to harness ambient sunlight for water release from harvesting devices, thereby enhancing energy efficiency. Similarly, carbon capture technologies can utilize waste heat from industrial processes, rendering them more economical and sustainable compared to competing systems.

However, challenges in scalability and precise molecular release control persist. While producing MOFs in large quantities is feasible, COFs production has not reached such scales yet. I am optimistic that improvements will come swiftly. Optimizing water retention is essential; we must strike the right balance between excessive and insufficient retention.

We are now leveraging artificial intelligence to streamline MOF and COF optimization, making the design process more efficient. Generally, while generating a basic MOF or COF is straightforward, achieving one with finely-tuned properties can be time-consuming, often taking a year. The integration of AI could significantly accelerate this timeline; our lab has successfully doubled the speed of MOF creation by employing large-scale language models.

What promising applications of reticular chemistry should capture public interest?

Reticular chemistry is a thriving field, with millions of new MOFs yet to be synthesized. One intriguing concept involves utilizing MOFs to replicate the catalytic functions of enzymes, enhancing the efficiency of chemical reactions important in drug development and other fields. Some MOFs have demonstrated capabilities comparable to enzymes but with improved longevity and performance, making them ripe for medical and therapeutic applications over the next decade.

An exciting future application lies in “multivariate materials.” This research, largely conducted in my lab, aspires to create MOFs with varied internal environments. By employing different modules paired with varying compounds, we can develop materials that selectively and efficiently absorb gases. This approach encourages chemists to expand their thinking beyond creating uniform structures toward designing heterogeneous frameworks that incorporate diverse elements.

What gives you confidence in the future of MOF and COF innovations?

We’ve merely scratched the surface, with no shortage of concepts for exploration. Since the 1990s, this field has flourished, and while interest in many areas declines over time, that hasn’t occurred here. An exponential rise in patents related to MOFs and COFs reflects ongoing curiosity and the pursuit of novel applications. I appreciate how this research links organic and inorganic chemistry, as well as engineering and AI, evolving beyond traditional chemistry into true scientific frontiers.

I genuinely believe we are at the cusp of a revolution. While it may not always feel that way, something extraordinary is transpiring. We can now design materials in unprecedented ways, connecting them to innovative applications that were once unimaginable.