A method to effectively scavenge highly mobile radioiodide into a solid material was developed. Under an anaerobic condition, as copper(II) was strongly associated with bicarbonate (HCO3 −) in solution, malachite quickly formed, and then it was gradually transformed to a compact crystal of CuI (marshite) attracting iodide. The formation of CuI crystal was principally led by the spontaneous Cu-I redox reaction centering around the copper phase over the presence of sulfate (SO4 2−). The transformed CuI crystal was poorly soluble in water. Interestingly, this redox-induced iodide crystallization was rather promoted over the existence of anionic competitors (e.g., HCO3 − and SO4 2−). Unlike the conventional methods, these competing anions positively behaved in our system by supporting that the initial malachite was more apt to be reactive to largely attract highly mobile I−. Under practical environments, such a selective I− uptake and fixation into a crystalline form will be a promising way to effectively remove I− in a great capacity.

• Seung Yeop Lee(Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon) Corresponding author
• Sang-Ho Lee(Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon)
• Jin-Seok Kim(Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon)
• Jang Soon Kwon(Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon)