Glycerol-based deep eutectic solvents for efficient and reversible iodine uptake from vapour phase.

The efficient capture and recovery of radioactive iodine (I₂) is crucial for nuclear safety and environmental protection. In this study, we propose some glycerol (Gly)-based deep eutectic solvents (DESs) as novel and promising solvents for iodine uptake from the vapour phase. Depending on the cholinium salt (Ch) selected as hydrogen bond acceptor (iodide or chloride) and its relative ratio with respect to glycerol (1:2 or 1:3), the I uptake approaches or even overcomes the 300 ms% with ChCl:Gly 1:2 showing the best performance with 4 g g after 24 h. Moreover, the captured I can be effectively (almost 80%) released showcasing the potential of DESs as iodine sponges. Finally, the exploitation of Raman spectroscopy proves the speciation of I-based species within the DES, paving the way for further engineering of these systems. Our results highlight Gly-based DES as a sustainable and cheap solvent for effective and semi-reversible I sponges.