Porous Organic Cage as an Efficient Platform for Industrial Radioactive Iodine Capture

Abstract

Herein, we firstly develop porous organic cage (POC) as an efficient platform for highly effective radioactive iodine capture under industrial operating conditions (typically ≥150 °C), ≤150 ppmv of I₂). Due to the highly dispersed and readily accessible binding sites as well as sufficient accommodating space, the constructed NKPOC-DT-(I^-) (NKPOC=Nankai porous organic cage) demonstrates a record-high I₂ uptake capacity of 48.35 wt % and extraordinary adsorption capacity of unit ionic site (~1.62) at 150 °C and 150 ppmv of I₂. The I₂ capacity is 3.5, 1.6, and 1.3 times higher than industrial silver-based adsorbents Ag@MOR and benchmark materials of TGDM and 4F-iCOF-TpBpy-I^- under the same conditions. Furthermore, NKPOC-DT-(I^-)Me exhibits remarkable adsorption kinetics (k₁=0.013 min^-1), which is 1.2 and 1.6 times higher than TGDM and 4F-iCOF-TpBpy-I^- under the identical conditions. NKPOC-DT-(I^-)Me thus sets a new benchmark for industrial radioactive I₂ adsorbents. This work not only provides a new insight for effectively enhancing the adsorption capacity of unit functional sites, but also advances POC as an efficient platform for radioiodine capture in industry.