Soft Self-Templating Approach-Derived Covalent Triazine Framework with Bimodal Nanoporosity for Efficient Radioactive Iodine Capture for Safe Nuclear Energy
Monojit Das, Sourav Kumar Sarkar, Yoti Shankar Patra, Anupam Manna, Soumya Mukherjee, Sanjib Das
Abstract
To achieve a superior removal efficiency of iodine from different phases relevant to radioactive iodine emission (129I/131I) for safe nuclear energy, optimized porous architectures with high surface area and large pore volume featuring appropriate pore size/shape and distribution along with a suitable chemical environment are sought. Herein, we report a soft self-templating synthesis strategy utilizing a low-cost and easily accessible 2,5-dimethoxy terephthalonitrile (LOMe) monomer to prepare a nitrogen/oxygen codoped nanoporous covalent triazine framework (MeO-CTF600) possessing an extremely high specific surface area of 2731 m2 g–1 and a record pore volume of 3.33 cm3 g–1. Interestingly, this framework shows extensive bimodal nanoporosity ranging from the micropore (1–2 nm) to narrow mesopore (2–10 nm) region, necessary to achieve superior iodine adsorption. MeO-CTF600 exhibits outstanding iodine capture performance from iodine vapor (578 wt %), including aqueous (221 wt %) and organic (849 mg g–1) solutions of iodine, under nuclear-fuel reprocessing conditions (348 K) compared to benchmark materials. In addition, the framework shows extremely fast adsorption kinetics and regenerability, making it a promising adsorbent tackling all sorts of radioiodine contamination toward clean and safe nuclear power sources.