Reversible capture and release of I2 with dechlorinated porous organic polymer

Abstract

In recent years, porous organic polymers (POPs) possess a remarkable potential as adsorbents for heavier halogen (I2 and Br2) capture in the fields of environmental treatment and industrial production. How to improve iodine adsorption properties through efficient molecular structure design is still worth exploring. In this work, a novel nitrogen-rich POP, defined as POP-TT, for iodine capture is designed and easily obtained by reacting 2,4,6-trichloro-1,3,5-triazine (TCT) and tris(4-aminophenyl) amine (TAPA) with the aid of dechlorination agent under mild condition, inspired by the significant enhancement of iodine capture with N-rich heterocyclic structure. The proposed POP-TT shows good stability and porosity even in high-salt solutions. Profiting from the nitrogen-rich skeleton and phenyl groups of POP-TT and strong charge-transfer interaction between polymer framework and adsorbed iodine, the proposed POP-TT exhibits excellent affinity with uptake capacity of 4.62 g g−1 for iodine vapor and removal efficiency of 86.8 % for iodine aqueous solution. Good retention behavior and recycling capacity are also observed for POP-TT. This work provides a practical guide for designing heavier halogen adsorbents by using dechlorinated porous organic polymers.