AER/Inorganic Seminar – Sheng Yu

About the event

Speaker: Sheng Yu

Group: Dr. Jack Zhang

Title: Hierarchically Porous UiO-66 for Iodine Diffusion and Conversion

Abstract: Radioiodine released during nuclear accidents is mainly present as volatile I₂, which requires sorbent materials with high uptake capacity, fast adsorption, and good reusability. In this work, we developed a scalable one-step solvothermal method to synthesize defect-rich, hierarchically porous UiO-66 (HP-UiO-66) and its amino-functionalized derivatives. These materials show greatly enhanced iodine capture compared with highly crystalline UiO-66. In particular, HP-UiO-66-(NH₂)₂ achieved the highest iodine uptake of 3046.75 mg g⁻¹ under dry I₂ vapor at 85 °C, together with excellent retention stability over time. Spectroscopic analysis and theoretical calculations reveal that hierarchical porosity improves iodine diffusion into the crystals, while amino groups promote iodine conversion from molecular I₂ to iodide species such as I₃⁻ and polyiodides. Under humid conditions, iodine uptake decreases because of competition from water molecules. We also demonstrate efficient regeneration by air heating, giving high recovery rates and longer sorbent lifetime. Overall, this work provides new insights into how defect engineering and functional-group design can improve Zr-MOF adsorbents for radioiodine capture and regeneration.