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.