Effect of aluminum metal surface on oxidation of iodide under gamma irradiation conditions

Abstract

The effects of aluminum surface on I− oxidation under gamma irradiation were investigated. Without irradiation, only O2 oxidized I− at pH < 2, and aluminum expedited the oxidation reaction. With irradiation, the radiolysis products from water and air oxidized I− into $${{\text{I}}_{3}}^{ - } .$$ At pH 6, the H2O2 radiolysis product reduced $${{\text{I}}_{3}}^{ - }$$ into I−. A smaller amount of $${{\text{I}}_{3}}^{ - }$$ was observed in pH 1.9 and 3.3 solutions in contact with aluminum under irradiation because oxidants preferentially oxidize aluminum rather than I−. Moreover, for pH < 6.0, even less $${{\text{I}}_{3}}^{ - }$$ was formed by aluminum exposed to air because air radiolysis products also preferentially oxidized aluminum.