Reaction-Induced Post-Activated Nanotrap Strategy for Leakage-Resistant Immobilization of Radioactive Organic Iodide

Immobilizing radioactive organic iodides (ROIs) is essential for radioactive-pollution remediation. However, conventional ROI sorbents often suffer from I^- leakage, and the atomic-level mechanisms underlying ROI immobilization remain unclear. Herein, a reaction-induced postactivated nanotrap strategy is proposed for the leakage-resistant immobilization of trace-level methyl iodide. The nanotrap in a stable metal-organic framework (SCU-365) undergoes in situ activation by methylation during chemisorption and then precisely confines the generated I^-, which enables the crystallographic visualization of chemisorbed ROI for the first time. Structural and computational analyses reveal that the synergy of multiple weak interactions for I^- complexation rivals the strength of a covalent bond, endowing SCU-365 with exceptional leakage resistance superior to that of state-of-the-art ROI sorbents. This work proposes a novel strategy for antileakage material design for nuclide sequestration and fills the gap of understanding how materials interact with ROI.