Regenerable Covalent Organic Frameworks for Photo-enhanced Uranium Adsorption from Seawater

Uranium is a key resource for the development of the nuclear industry, and extracting uranium from the natural seawater is one of the most promising ways to address the shortage of uranium resources. Herein, a semiconducting covalent organic framework (named NDA-TN-AO) with excellent photocatalytic and photoelectric activities was synthesized. The excellent photocatalytic effect endowed NDA-TN-AO with a high anti-biofouling activity by generating biotoxic reactive oxygen species and promoting photoelectrons to reduce the adsorbed U^VI to insoluble U^IV , thereby increasing the uranium extraction capacity. Owing to the photoinduced effect, the adsorption capacity of NDA-TN-AO to uranium in seawater reaches 6.07 mg g^-1 , which is 1.33 times of that in dark. The NDA-TN-AO with enhanced adsorption capacity is a promising material for extracting uranium from the natural seawater.