Efficient adsorption of iodine by three-dimensional organic polymers synthesized by single step substitution and mechanism study

In this paper, we report the preparation of a novel three-dimensional organic polymer synthesized via a one-step substitution reaction utilizing dl-dithiothreitol and 2,4,6-tribromomethyltrimethylbenzene as raw materials. This polymer features a straightforward preparation process, low synthesis cost, and potential for large-scale production. The structural characterization of the polymer was conducted using various techniques, including solid-state carbon-13 nuclear magnetic resonance ( 13 C NMR), infrared spectroscopy (IR), thermogravimetric analysis (TGA), and powder X-ray diffraction (PXRD). Building on its structural characteristics, we further investigated the polymer’s adsorption capacity for both gaseous iodine and iodine in aqueous solutions. Experimental results confirm that the polymer exhibits efficient and selective iodine adsorption with no structural alteration before and after the capture process. The maximum adsorption capacity for iodine vapor reached 4.60 g g −1 . For aqueous solutions with concentrations of 0.12 mmol L −1 and 0.30 mmol L −1 , the maximum adsorption capacities were determined to be 6.25 mg g −1 and 24.58 mg g −1 , respectively. Extensive density functional theory (DFT) calculations revealed that multiple noncovalent interactions, including I−I···π, C−H···I, and O−H···I bonding, as well as electrostatic interactions between the polymer and I 2 /I 3 - species, collectively account for its exceptional iodine trapping capacity. • A novel three-dimensional organic polymer (DTTB3) was designed. • DTTB3 exhibits good iodine absorption for iodine vapor and aqueous iodine. • Density functional theory calculations explore adsorption mechanism. • This work offers a new approach to addressing the recycling of iodine.