Researchers have developed a covalent organic framework material able to improve the process of extracting uranium from seawater,according to a study detailed by Dr Xishi Tai of Weifang University and Dr Zhenli Sun of North China Electric Power University.The team's findings,published in Sustainable Carbon Materials,demonstrate how careful control of the stacking geometry in sulfonic covalent organic frameworks-known as S-COFs-produces a selective binding pocket for uranium ions.
Seawater holds roughly 4.5 billion tons of uranium,but extraction is complicated by low uranium concentration and the presence of other ions.The new AB-stacked S-COFs employ sulfonic group coordination to target uranium through a four-point bond,achieving about 1,000 times higher binding affinity than the AA stacking mode.
Testing in natural seawater showed the AB-stacked S-COF could extract 31.5 milligrams of uranium per gram of sorbent in one day,exceeding previous performance records.The material maintained selectivity,minimizing uptake of competing ions such as vanadium."Our study introduces a new design concept called stacking mode engineering,"said Dr Tai."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."
Dr Sun noted,"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."
The research supports the potential to utilize uranium from ocean water as a long-term nuclear fuel source if industrial deployment becomes feasible.The authors stress that future work must ensure materials are scalable,durable,and cost-effective for practical extraction and regeneration.