Porous materials based on organic macrocyclic molecules synthesized through Schiff base chemistry for iodine adsorption

Abstract

Radioactive iodine is a harmful pollutant in gaseous nuclear waste that can cause irreversible damage to both humans and the environment. The organic macrocyclic molecules OMM-1 and OMM-2 were synthesized through a Schiff-base reaction and could be handled easily and efficiently. Nitrogen adsorption experiments confirmed the porous structure of the OMM powders. The OMM-1 powder exhibited excellent iodine vapor capture properties, with a maximum adsorption capacity of up to 421.9 wt%. This exceptional iodine vapor capture capability likely arose from the porous structure; furthermore, charge transfer complexes might form between iodine and the aromatic systems containing imine bonds. More importantly, it was found that the iodine adsorption capacity remained as high as 99.5% after repeating the adsorption–desorption experiments 5 times. This research has potential applications and might provide alternative strategies for the treatment of radioactive iodine vapor in nuclear waste gas.