Efficient and selective uranium extraction from seawater using recyclable hydrophobic deep eutectic solvents

Abstract The recovery of uranyl ions (UO 2 2+ ) from seawater is essential for sustainable nuclear energy development, yet effective extractants remain limited. In this work, three novel phosphoryl‐based hydrophobic deep eutectic solvents (HDESs), namely [TOPO][THY], [DEHPA][THY], and [TBP][THY], were synthesized for the selective extraction of UO 2 2+ . The effects of operational parameters on extraction performance and distribution coefficients were systematically evaluated. Under optimal conditions, all HDESs achieved single‐stage extraction efficiencies exceeding 99.9%. Thermodynamic analysis revealed that the extraction process was exothermic. Efficient back‐extraction of UO 2 2+ and regeneration of HDESs were realized using ammonium sulfate and sulfuric acid. The formation mechanism of HDESs and their interaction with UO 2 2+ were elucidated by FT‐IR, 1 H‐NMR, and quantum chemical calculations (QC). Furthermore, extraction tests using simulated Yellow Sea seawater demonstrated that the HDESs maintained high efficiency in complex matrices, highlighting their potential for uranium recovery from seawater.