A research team in Qingdao has developed a porous material called PhosCage that can selectively bind uranium in seawater. In laboratory tests using natural seawater, it captured 50.4 milligrams of uranium per gram of adsorbent.
The result is more than eight times the target of six milligrams per gram previously set by the United States Department of Energy. The material arranges chemical groups to capture uranyl ions even in water containing many competing substances.
The researchers also produced a more practical bead form. It achieved 22.55 milligrams per gram and could be reused for seven cycles, an important consideration for future costs and durability.
This remains a research result rather than commercial extraction from the ocean. Large scale manufacturing, energy use, environmental effects and long term behaviour in seawater will all need to be tested before practical deployment can be assessed.
