Synergistic Coordination Mechanism of Aminophosphonate-Functionalized UiO-66 for Enhanced Uranium(VI) Adsorption

The stringent environmental regulations on uranium-containing wastewater have rendered traditional treatment methods largely inadequate, creating an urgent demand for high-performance and stable adsorbents. In this study, the modified UiO-66 with aminophosphonate groups (UiO-66-NH2–P) was used to enhance its U(VI) removal capacity from water through the synergistic effect of multifunctional groups. U6NP retains a well-defined MOF framework after acid immersion(pH 1–2). Under optimal conditions, the maximum U(VI) adsorption capacity reaches 320.81 mg/g. The adsorption behavior conformed to the PSO kinetic equation and the Langmuir model, indicating a spontaneous endothermic process. Furthermore, density functional theory (DFT) calculations, combined with optimized fitting using a cluster model, were performed to analyze various coordination modes of UO22+ in this system. The results provide atomic-level insights for the rational design of high-performance and high-stability adsorbent materials.