Novel N-rich porous organic polymers for reversible iodine capture and selective detecting of Fe (III)

Abstract

Developing porous organic materials for removing radiotoxic iodine from nuclear plant waste and heavy metal Fe³⁺ is significantly relevant to environmental remediation. To achieve reversible iodine adsorption, 1,6-dibromopyrene is used as the matrix, a unique nitrogen-rich porous organic polymer containing pyrene (PEMA) was tailor-made by introducing a triazine structure through a schiff base reaction. This polymer exhibits high affinity and adsorption capacity for iodine owing to its effective electron-rich adsorption sites, an extended π-conjugated structure and hierarchically porous structure. PEMA displayed remarkable adsorption capacities for saturated iodine vapor (3.19 g g⁻¹) and iodine n-hexane solution (250.39 mg g⁻¹). Furthermore, the fluorescence characteristic of PEMA has been employed for the selective detection of Fe³⁺ with high sensitivity with a low detection limit of 0.84 μM among a range of metal ions. Meanwhile, PEMA also demonstrates a good adsorption capacity for Fe³⁺, amounting to 48 mg g⁻¹. These results suggest that PEMA possesses excellent iodine capture capabilities along with detection and adsorption capacities for Fe³⁺, making it a promising candidate for environmental remediation.