Uranium Adsorption and Extraction Strategies

Uranium recovery and remediation represent critical components of sustainable nuclear fuel supply and environmental protection. The predominant form in aqueous systems, U(VI), often exists as the uranyl ion (UO22+), which exhibits high solubility and mobility. Effective extraction strategies centre on materials and processes that combine high affinity for uranyl species with robustness under variable chemical conditions. Adsorbent design has advanced from simple ion‐exchange resins to porous nanomaterials, including covalent organic frameworks (COFs), metal–organic frameworks (MOFs) and functionalised carbon matrices, each engineered to present abundant binding sites such as amidoxime groups or tailored heteroatoms. Complementary approaches harness electrocatalytic and photocatalytic reduction to convert U(VI) into sparingly soluble U(IV) species for facile separation. Integration of built‐in electric fields, bio‐inspired chelating motifs and anti‐biofouling chemistries has improved selectivity and operational lifetime in challenging matrices such as seawater and industrial effluents. Current research emphasises sustainable fabrication, regenerability and real-time monitoring capabilities to meet the dual demands of uranium resource recovery and environmental stewardship.

Research from Nature Portfolio

A fluorescent covalent organic framework has been engineered with sp2-carbon conjugation and amidoxime-functionalised linkers to achieve rapid and ultra-sensitive detection alongside high‐capacity UO22+ adsorption. Exceptional chemical and radiation stability, combined with accessible one-dimensional channels, yield uptake capacities exceeding 400 mg g⁻¹ and real-time response times under two seconds, demonstrating a dual-function platform for simultaneous monitoring and extraction. Bio-inspired porous nano-traps emulate protein-like second-sphere interactions by incorporating chelating moieties and assistant groups into robust frameworks. These materials reach uptake capacities above 500 mg g⁻¹ and retain performance in natural seawater, revealing the synergistic role of hydrogen bonding and coordinative interactions in boosting uranyl affinity. A DNA-based hybrid hydrogel adopts uranyl-binding strands from DNAzymes to form a ‘nano-pocket’ that selectively isolates UO22+ from competing cations in seawater, achieving high selectivity factors and demonstrating the versatility of biopolymer assemblies in radionuclide recovery.

Uranium Adsorption and Extraction Strategies publication trend

The graph below shows the total number of articles in uranium adsorption and extraction strategies across all publications each year (not limited to Nature Index journals).

Technical terms

Adsorption: The adhesion of ions or molecules to a solid surface via physical or chemical interactions.

Uranyl (UO22+): The dominant hexavalent uranium species in aqueous solutions, characterised by a linear O=U=O structure.

Covalent Organic Framework (COF): A crystalline, porous polymer network composed of light elements linked by strong covalent bonds, offering high surface area and tunable functionality.

Amidoxime Functional Group: A ligand moiety containing –C(NOH)NH₂ that binds uranyl ions with high selectivity, widely employed in uranium adsorbents.

Heterojunction: An interface between two semiconductor materials with differing band structures, facilitating charge separation for photocatalytic processes.

Photocatalysis: A process in which light irradiation induces electron–hole pairs in a semiconductor, driving redox reactions such as reduction of U(VI) to U(IV).

Electrocatalysis: The acceleration of electrochemical reactions at an electrode surface, often used to deposit or reduce metal ions selectively.

References

1. Highly selective removal of U(VI) from aqueous solutions by porous nanomaterials. EcoEnergy (2024).
2. Rich electron delocalization structure in carbon nitride inducing radical transfer for high‐performance photocatalytic uranyl reduction. Carbon Energy (2024).
3. Photo‐enhanced uranium recovery from spent fuel reprocessing wastewater via S‐scheme 2D/0D C3N5/Fe2O3 heterojunctions. SusMat (2024).
4. Regenerable and stable sp2 carbon-conjugated covalent organic frameworks for selective detection and extraction of uranium. Nature Communications (2020).
5. Bio-inspired nano-traps for uranium extraction from seawater and recovery from nuclear waste. Nature Communications (2018).
6. DNA nano-pocket for ultra-selective uranyl extraction from seawater. Nature Communications (2020).
7. A Universally Applicable Strategy for Construction of Anti‐Biofouling Adsorbents for Enhanced Uranium Recovery from Seawater. Advanced Science (2019).