Porous Aromatic Framework with Multifunctional Sites for Effective Recovery of Various Trace Iodine Species From Water.

Recovery of environmental iodine is of great significance for both recycling iodine resources and addressing iodine pollution. However, iodine is highly sensitive to environmental factors and exists in various chemical species, which complicates the recovery of trace iodine in aqueous systems. Here a porous aromatic framework (iPAF-TEPT) is presented with multifunctional adsorption sites for efficient recovery of various iodine species, including molecular iodine (I2), iodide (I- and I3 -). The material utilizes a synergistic strategy combining charge-transfer interactions and Coulomb interactions to effectively adsorb different iodine species. Thanks to its high density of accessible ion exchange sites for I⁻ and I3⁻, and nitrogen-rich sites for I2, iPAF-TEPT demonstrates an unprecedented adsorption capacity for various iodine forms. Notably, iPAF-TEPT achieves exceptional removal efficiency for trace iodine pollutants, even at concentrations as low as 100 ppb, making it the first promising single-framework material for highly efficient treatment of aqueous iodine contamination.