Universal Scaling Relationship To Screen an Efficient Metallic Adsorbent for Adsorptive Removal of Iodine Gas under Humid Conditions: First-Principles Study

Safe control and removal of radioactive iodine gases (I-129 and I-131) leaking from the accidents in chemical factories or nuclear industries are of importance because of their critical damage to the biosphere. We study the adsorptive removal of the off-gaseous iodine using transition metals of group 10 and group 11 under humid conditions. First-principles calculations enable to capture key adsorption natures of iodine and water molecules on the adsorbent surfaces. The underlying mechanism is analyzed by thermodynamic free energies, electronic structures, and surface work function changes. Our results unveil why silver metal shows notably outstanding efficiency for the iodine removal. We propose an innovative and insightful map to guide sorting out the best metal adsorbents and impregnants for dramatic improvement of the adsorptive removal of the radioactive iodine gas. Our study is useful for preventing critical risks from chemical and nuclear accidents