A Novel Hierarchical Three-Dimensional Ultramicroscopic Porous Bio-Adsorbent for Robust and Selective Uranium Extraction from Natural Seawater

An economical and high energy storage adsorbent remains a crucial task for energy sources and environmental safety. Aiming for improving the mass transfer rate, storage, support for high-temperature catalysis, energy conversion and nanoscale building blocks for conductive polymer composites, a new strategy for three-dimensional ultramicroporous (>2 nm) bio-based adsorbent has been developed. Herein, a facile approach to fabricate hierarchical three-dimensional porous frameworks (AO-Fc), where amidoxime groups are structure-directing agents to select uranium from seawater. AO-Fc suffered minimum interference with uranium adsorption capacity of 8.57 mg/g from seawater and most of the adsorption occurred within 5 days and the equilibrium reached around 10 days of field analysis. The porous surfaces of AO-Fc exhibited more chelating sites, which attributed to fast kinetics, high uranium adsorption and hydrophilic nature. The hydrophilic properties of AO-Fc enhanced the contact between the uranium and chelating sites and prompt fast kinetics and selectivity in presence of other competing ions. Because of its stable structure, AO-Fc exhibited a long life span with weight loss and benefiting from the low-cost raw material source (Fc) revealed AO-Fc could be applied as an economical and efficient adsorbent for uranium extraction from seawater at an industrial scale