Zero-valent silver nanoparticles functionalized populus tomentosa fiber for efficient capture and immobilization of iodine vapor

With the rapid development of nuclear energy, the removal of radioactive iodine generated during spentfuel reprocessing has become increasingly important. Based on the unique straw-like structure of populus tomentosa fiber (PTF) and the highly active iodine vapor capture ability of zero-valent silver nanoparticles (PTF@Ag⁰NP), an Ag⁰NP composite functional material with highly efficient iodine vapor capture capability was synthesized from biowaste PTF through ultrasonic and high-temperature hydrothermal methods in this study. The iodine capture experiment demonstrated that PTF@Ag⁰NP exhibits rapid iodine capture efficiency, reaching dynamic equilibrium within 4 h and a maximum capture capacity of 1008.1 mg/g. Density functional theory calculations show that PTF@Ag⁰NP exhibits extremely high chemical reactivity towards iodine, with a reaction binding energy of ?2.88 eV. Additionally, the molecular dynamics of PTF@Ag⁰NP indicate that there is no atomic displacement at 77 ℃, indicating the excellent temperature stability of the material at the operating temperature. The capture mechanism suggests that iodine vapor primarily reacts with Ag⁰NP to form AgI, and that the hydroxyl groups in PTF can also effectively capture iodine vapor by adsorption induction. In conclusion, PTF@Ag0NP is expected to be an effective candidate adsorbent material for removing radioactive iodine vapor from exhaust gases during spent-fuel reprocessing.