The oxidation of UF 4 in FLiNaK melt and its electrolysis

The oxidation of UF 4 in LiF–NaF–KF (FLiNaK) melt with oxygen sparging was conducted at 823 K and analyzed by in situ infrared spectrometer, UV–Vis absorption spectrometer, and other characterizations with thermodynamic calculations, indicating UF 4 was converted to UO 2 F 2 with the following reaction mechanism: 2UF 4 (l) + O 2 (g) + 2H 2 O(g) = 2UO 2 F 2 (l) + 4HF(g). Cyclic voltammetry measurements showed that the reduction of UO 2 2+ in oxidized melt exhibited two steps both with one exchanged electron: UO 2 2+ + e − → UO 2 + and UO 2 + + e − → UO 2 . By potentiostatic electrolysis, the product of UO 2 was obtained with nanoscale triangular sheet structure.