Ligand Defect Engineering of Amidoximated Metal–Organic Frameworks for Highly Efficient Uranium Extraction From Seawater

Why It Matters

The breakthrough offers a scalable, high‑performance adsorbent that could make seawater a viable uranium source, easing supply constraints for the expanding nuclear energy sector.

Key Takeaways

• Defect engineering boosts MOF uranium uptake
• UiO-66-3BA-AO adsorbs 904 mg/g in 90 min
• Extracts 26.9 mg/g from seawater over 4 weeks
• Shows high selectivity and antibacterial properties
• Easily loaded onto various carriers for deployment

Pulse Analysis

The nuclear industry’s rapid growth has intensified the search for alternative uranium supplies, and seawater—containing roughly 3 ppm of the element—represents an almost limitless reservoir. However, extracting uranium from such dilute, salty matrices has long been hampered by slow kinetics and poor selectivity of conventional adsorbents. Recent advances in materials science, particularly the development of metal‑organic frameworks (MOFs) with tailored pore environments, promise to overcome these barriers by offering high surface areas and tunable chemistry.

In the latest study, scientists applied a ligand‑modulation approach to introduce controlled defects into UiO‑66‑type MOFs and grafted amidoxime groups, which have a strong affinity for uranyl ions. The resulting UiO‑66‑3BA‑AO material exhibited an unprecedented adsorption capacity of 904 mg g⁻¹ and reached equilibrium in just 90 minutes—metrics that dwarf earlier MOF‑based sorbents. Moreover, when deployed in real seawater, the framework extracted 26.9 mg g⁻¹ of uranium over a month, demonstrating that defect engineering not only accelerates kinetics but also enhances overall uptake under realistic conditions.

Beyond raw performance, the new adsorbents combine selectivity against competing ions, resistance to biofouling, and straightforward regeneration, making them attractive for large‑scale deployment. Their ability to be coated onto various support materials simplifies integration into existing seawater‑intake infrastructure, potentially lowering capital costs. As the global push for low‑carbon energy intensifies, such high‑efficiency, recyclable sorbents could play a pivotal role in securing a stable uranium supply chain, reducing reliance on terrestrial mining, and advancing the commercial viability of marine uranium extraction.