Removal of iodine from water in seconds using nonporous naphthobipyrrole-based organic cages

• • Type-II Me-NBP-Cage and Et-NBP-Cage achieve >99% iodine removal from water within seconds, despite having low BET surface areas of 33.4 and 2.3 m2 g−1, respectively, demonstrating that porosity is not a prerequisite for ultrafast adsorption. • • The amorphous, small particles (2–6 μm) of type-II materials exhibit superior removal kinetics compared to crystalline, larger particles (10–80 μm) of type-IV materials, indicating that morphology and particle size critically influence adsorption performance. • • Et-NBP-Cage can be recycled by simple washing with acetonitrile, maintaining flow-through removal efficiency at the same level after five cycles, offering a cost-effective and sustainable regeneration method. • • The nonporous nature of these cages, combined with their rapid kinetics, challenges the conventional reliance on high surface area for iodine sorbents, potentially enabling new material design strategies for nuclear waste treatment.