A Zr/Ti-based bimetallic AO-UiO-66 framework for effective uptake of radioactive iodine

To develop porous solid-state materials for effective capture of radioactive iodine in both vapor and solution phases is of great importance. In this work, a Zr/Ti-based bimetallic metal-organic framework (AO-UiO-66-ZrTi11) was synthesized via a simple solvothermal method using 2, 5-bis (allyloxy)terephthalic acid, ZrCl4 and Cp2TiCl2. This MOF solid was fully characterized and extensively evaluated for its I2 capturing performance. AO-UiO-66-ZrTi11 demonstrated significantly enhanced I2 uptake capacity, achieving as high as 2.46 g·g-1 for iodine vapor and 1084.4 mg·g-1 for iodine/cyclohexane solution. Kinetic studies of iodine adsorption from solution revealed rapid kinetics, with the process fitting well to the pseudo-second order kinetic model. The superior adsorption performance of AO-UiO-66-ZrTi11 for iodine can be attributed to its unique bimetallic structural features and functional groups. This work provides valuable insights for the further development of efficient adsorbents towards capturing radioactive iodine.