Efficient Enrichment of Iodine by Supported Ionic Liquid with Three Effective Adsorption Sites: Heteroatoms, Fused Aromatic Rings and Ionic Bond

•An iodine adsorbent with three adsorption sites was prepared by one-step reaction.•[N4444]4PTC could interacts with guest iodine molecules through heteroatoms, fused aromatic rings and ionic bond.•The iodine vapor capture capacity of the [N4444]4PTC@MF composite was as high as 5.81 g/g.•This is of great significance for the rational design of multi-site adsorbents.