High-Capacity Amidoxime-Functionalized β-Cyclodextrin/Graphene Aerogel for Selective Uranium Capture.

Uranium extraction from seawater is a grand challenge of mounting severity as the energy demand increases with a growing global population. An amidoxime-functionalized carboxymethyl β-cyclodextrin/graphene aerogel (GDC) is developed for highly efficient and selective uranium extraction via a facile one-pot hydrothermal process. GDC reaches equilibrium in 1 h, and the maximum adsorption capacity calculated from Langmuir model is 654.2 mg/g. Benefiting from the chelation and complexation reaction, the obtained GDC has an excellent selectivity even when the competitive cations, anions, and oil pollutants exist. In addition, the aerogel possesses great mechanical integrity and remains intact after 10 compression cycles. Meanwhile, the GDC can be easily regenerated and maintains a high reusability of 87.3% after 10 adsorption-desorption cycles. It is worthwhile to mention that GDC exhibits an excellent extraction capacity of 19.7 mg/g within 21 days in natural seawater, which is greatly desired in uranium extraction from seawater.