Synthesis of mesoporous salen polymer nanospheres for highly efficient photocatalytic extraction of uranium from seawater

Efficient uranium extraction from seawater is essential to the long-term sustainability of nuclear energy, yet the rational design of high-performance materials for this purpose remains a formidable challenge. Herein, we develop an ionization regulated self-assembly strategy to synthesize mesoporous Salen polymer nanospheres (mDSR) for photocatalytic uranium extraction. Partial ionization improves the aqueous solubility of otherwise insoluble Salen ligands and enhances their reactivity towards formaldehyde, while preserving sufficient precursor-micelle interactions for co-assembly, thereby directing the formation of ordered mesostructures. This strategy is facile, universal, and it can accommodate a series of structurally distinct Salen ligands, enabling the modular construction of mesoporous polymers with programmable molecular functions. The mDSR nanospheres feature a large pore size (6.2 nm), a high surface area (68 m2 g−1), and intrinsic photocatalytic activity. As a result, under simulated sunlight and without sacrificial agents, mDSR achieves a high uranium uptake capacity of 867 mg U g−1 from a 10 ppm U(VI) solution, outperforming most adsorbents. This protocol establishes a new paradigm for functional mesoporous polymers.