A team of scientists has developed a groundbreaking material that dramatically boosts the ability to extract uranium from seawater, addressing one of the key challenges in the sustainable development of nuclear energy. The study introduces a special type of covalent organic framework (COF) that shows record-high efficiency and selectivity in isolating uranium from the vast reservoirs hidden in the world's oceans.
Uranium-235, a primary fuel for nuclear power, is essential to the global effort to curb carbon emissions and move toward carbon neutrality. However, terrestrial uranium reserves are limited and estimated to last only about 70 more years at current rates of use. In contrast, seawater is believed to contain approximately 4.5 billion tons of uranium, enough to meet global energy demands for centuries. Yet the low concentration of uranium in seawater, along with the presence of competing ions and microorganisms, has posed a significant challenge to efficient extraction.
In a study published in Sustainable Carbon Materials, researchers Dr. Xishi Tai of Weifang University and Dr. Zhenli Sun of North China Electric Power University reveal a cutting-edge strategy using sulfonic covalent organic frameworks (S-COFs). These materials feature a precise stacking architecture that creates a highly specialized binding pocket for uranium extraction.
"Our study introduces a new design concept called stacking mode engineering," said Dr. Tai, lead author of the study. "By carefully controlling the geometric arrangement of the COF layers, we have created a confined space that perfectly matches the shape and coordination preferences of uranium ions."
The research focused on manipulating how the COF layers stack together. In what the authors describe as an AB stacking mode, sulfonic groups within the framework form a pocket that selectively binds uranium ions through a four-point coordination. This molecular-level precision delivers a major leap in performance.
The results are groundbreaking. The AB-stacked S-COFs showed a binding affinity approximately 1,000 times stronger than the traditional AA stacking mode. In tests with natural seawater, the material was able to extract 31.5 milligrams of uranium per gram of sorbent in just one day, a record-setting achievement. The material also demonstrated unprecedented selectivity, removing uranium while ignoring other ions like vanadium that often interfere in ocean-based extraction.
"This is the highest performance ever reported for uranium extraction from natural seawater," said Dr. Sun. "We believe our work opens new doors not only for uranium recovery but for designing materials suited to target specific ions in complex environments."
Beyond laboratory results, the authors highlight the importance of developing materials that are not only efficient but also durable, cost-effective, and scalable. Real-world applications will require materials that can withstand marine environments, be regenerated for reuse, and be produced in economic quantities.
Although there is still a long way to go before ocean-based uranium extraction becomes industrially viable, the authors believe the future is promising. "As technology advances, we expect to see broader use of smart materials like these in sustainable energy systems," Dr. Tai added.
The study reflects a continuing effort in the scientific community to harness seawater as a renewable resource for nuclear fuel, contributing to a stable and carbon-neutral energy future.
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Journal reference: Tai X, Sun Z. 2025. Extra-high extraction of uranium from seawater by covalent organic frameworks through structure geometry and functional active site modification. Sustainable Carbon Materials 1: e006
https://www.maxapress.com/article/doi/10.48130/scm-0025-0007
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About Sustainable Carbon Materials :
Sustainable Carbon Materials is a multidisciplinary platform for communicating advances in fundamental and applied research on carbon-based materials. It is dedicated to serving as an innovative, efficient and professional platform for researchers in the field of carbon materials around the world to deliver findings from this rapidly expanding field of science. It is a peer-reviewed, open-access journal that publishes review, original research, invited review, rapid report, perspective, commentary and correspondence papers.
