Graphene Oxide and Silver Ions Coassisted Zeolitic Imidazolate Framework for Antifouling and Uranium Enrichment from Seawater

Seawater environmental
limitation from antifouling due to microorganisms
presents a great challenge in uranium extraction from seawater. Herein,
a bifunctional graphene oxide-silver ions-zeolitic imidazolate framework-67
composite was successfully synthesized for minimizing the effects
of antifouling in the enrichment of uranium. A series of antialga
assays were carried out using Phaeodactylum tricornutum as a fouling template alga. Interestingly, the adsorbents clearly
display an algae inhibitory behavior with more than 80% alga death
rate after 7 days, as well as enhance U­(VI) adsorption performance
via the coassistance of graphene oxide and silver ions. Adsorption
amounts of composites reach 189.36 mg g–1 at a pH
7.0. In addition, composites still retain a high U­(VI) adsorption
amount which increases by 177% in comparison to the zeolitic imidazolate
framework-67 at pH 8.0 (nearly seawater pH). The adsorption experiment
was carried out in actual seawater, with the removal rate of U­(VI)
reaching nearly 70%, which proves that the graphene oxide and silver
ions coassisted zeolitic imidazolate framework-67 composites are applicable
to a seawater environment.