Photocatalytic capture of uranium via phosphorylated MOF@COF: Unveiling the dual functions from adsorption-reduction to uranium peroxide precipitation

Herein, phosphorylated MOF@COF (UiO-66-NH 2 @HDU-27-P) Type-II heterostructures were constructed to achieve selective and efficient uranium extraction. These composites were synthesized via the covalent linking of MOFs with COFs at varying ratios, and their electronic properties were analyzed using density functional theory (DFT) calculations. The optimized 6:1 composite exhibited exceptional performance, achieving (> 92.9 %) U(VI) removal in pure water and maintaining high efficiency across complex aqueous environments, including seawater. Mechanistic studies revealed that the Type-II heterojunction significantly enhances charge separation, enabling uranium capture through synergistic adsorption, photocatalytic reduction, and immobilization under non-sacrificial air conditions. This work provides a new paradigm for designing high-performance heterojunctions, offering a superior alternative to current materials for sustainable environmental remediation and uranium recovery.