Constructing Uranyl-Specific Nanofluidic Channels for Unipolar Ionic Transport to Realize Ultrafast Uranium Extraction

Abstract

High-speed capturing of uranyl (UO 2 2+ ) ions from seawater elicits unprecedented interest for the sustainable development of the nuclear energy industry. However, the ultralow concentration (∼3.3 μg L −1 ) of uranium element leads to the slow ion diffusion inside the adsorbent particle, especially after the transfer paths are occupied by the coexisted interfering ions. Considering the geometric dimension of UO 2 2+ ion (a maximum length of 6.04−6.84 Å), the interlayer spacing of graphene sheets was covalently pillared with phenyl-based units into twice the ionic length (13 Å) to obtain uranyl-specific nanofluidic channels. Applying a negative potential (−1.3 V), such a charge-governed region facilitates a unipolar ionic transport, where cations are greatly accelerated and co-ions are repelled. Notably, the resulting adsorbent gives the highest adsorption velocity among all reported materials. The adsorption capacity measured after 56 days of exposure in natural seawater is evaluated to be ∼16 mg g −1 . This novel concept with rapid adsorption, high capacity, and facile operating process shows great promise to implement in real-world uranium extraction.

Improving in vivo Uranyl Removal Efficacy of a Nano‐Metal Organic Framework by Interior Functionalization with 3‐Hydroxy‐2‐pyridinone

“…11.5 Å for two ligands), the pores in MIL‐101 still provide sufficient room to accommodate UO 2 2+ which is 6.04—6.84 Å in length. [ 37‐39 ] Taking the aforementioned advantages of MIL‐101 and HOPO ligands into consideration, we propose using HOPO functionalized MIL‐101 for the decorporation of uranium in vivo .…”

Enhanced Photocatalytic Reduction of U(VI) on SrTiO3/ g‐C3N4Composites : Synergistic Interaction

“…The concentration of uranyl ions in the aqueous solution and seawater were 20 mg/L by adding uranyl ions. No adsorption of U(VI) from seawater at 30 min dark reaction was probably due to other metal ions in seawater occupied the adsorption site, [42,43] whereas 88 % of U(VI) was photo-reduced within 15 min after illumination. These results showed that STO/CN can be used as the promising photocatalyst in photocatalytic reduction of U(VI) for seawater.…”

Theoretical and experimental investigations of enhanced uranium(vi) adsorption using a nitrogen doping strategy

“…10–12 Among these, adsorption has been widely used in wastewater treatment because this process has the advantages of being relatively simple, inexpensive and adaptable while also exhibiting good removal performance. 13–15 A variety of U( vi ) adsorbents have been successfully applied in the treatment of wastewater, mining drainage and seawater contaminated with U( vi ). 16–18 These materials have included mesoporous silica 19,20 and metal–organic frameworks 21,22 (which exhibit high porosity and functionalization), natural polymers 23,24 (which are inexpensive and biocompatible) and carbon-based nanomaterials 10,14,25 (which are highly stable with large specific surface areas and numerous functional groups).…”