New, efficient way to extract uranium from seawater reported

Limited terrestrial reserves: According to the study, “Extra-High Extraction of Uranium from Seawater by Covalent Organic Frameworks [COF] through Structure Geometry and Functional Active Site Modification,” land-based uranium resources could run out in as few as 70 years, given the current rate of consumption.

On the other hand, the ocean holds about 4.5 billion tons of uranium—a more than sufficient supply to meet the needs of nuclear energy on a global scale for thousands of years. However, extraction of this uranium is complicated by its low concentrations in seawater and the presence of competing ions and microorganisms.

The material: The research team developed a sulfonic COF material with an architecture designed to extract uranium ions through “stacking mode engineering,” said Xishi Tai, the lead author of the study. He explained in a news release, “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 sulfonic groups in the material function as pockets that selectively bind uranium ions, extracting them from seawater that is filtered through the material.

According to the researchers, the stacked sulfonic COFs “showed an exceptionally strong binding affinity, ultrafast adsorption kinetics, and record-high distribution coefficients.” In addition, the material demonstrated “unprecedented selectivity,” the news release summarized, “removing uranium while ignoring other ions like vanadium that often interfere in ocean-based extraction.”

Highest performance: Zhenli Sun, the study’s coauthor, said, “This is the highest performance ever reported for uranium extraction from natural seawater. We believe our work opens new doors not only for uranium recovery but for designing materials suited to target specific ions in complex environments.”

Continuing effort: Tai and Sun emphasized that further research is needed before their uranium extraction method might become a viable solution for the nuclear industry. With such promising results, however, the authors conclude their paper by saying, “We believe that uranium extraction from the ocean will open a new way for nuclear fuel preparation with the development of technology and science.”