Ultrahigh and economical uranium extraction from seawater via interconnected open-pore architecture poly(amidoxime) fiber

Effectively addressing global warming requires a rapid transformation of the ways in which energy is consumed, and nuclear power produces very low lifecycle carbon emissions. Efficient uranium extraction from unconventional uranium ore sources, such as the ocean, can provide a stable and long-term supply of nuclear fuel for nuclear power plants. Herein, we report an interconnected open-pore architecture poly(amidoxime) (PAO) fiber with PAO nanoparticles and a nano-channel structure (AO-OpNpNc) using a top-down design. A high uranium adsorption capacity of 17.57 mg-U per g-adsorbent in natural seawater and ultra-long service life of at least 30 cycles were obtained, which are the highest values among currently available adsorbents to our knowledge. Extended X-ray absorption fine structure (EXAFS) fits and density functional theory (DFT) computational studies suggest that PAO-bound uranyl is a cooperative chelating model. More importantly, uranium production costs could be reduced to $80.70-86.25 per kg of uranium with this fiber, which is similar to the uranium spot price of $86.68 per kg of uranium and lower than the costs of all currently available adsorbents. The exceptional durability of the AO-OpNpNc fibers suggests the possibility of economically producing nuclear fuel from the ocean.