Co-electrodeposition of U and Mo from a LiCl-KCl melt

Co-electrodeposition of uranium and molybdenum from a LiCl-KCl melt was investigated using cyclic voltammetry (CV), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The electrochemical study showed that the electrodeposition of Mo occurred from a molten LiCl-KCl eutectic at potentials more negative than −0.3 V vs. Ag|Ag+. Electrodeposition at a low overpotential range (between −0.3 V and −0.35 V) resulted in flat, thin Mo films, whereas greater overpotentials led to the growth of 3D films. Conditions for simultaneous electrodeposition of U and Mo were then optimized by varying the concentrations of UCl3 and MoCl3 and the electrodeposition method applied. At a constant potential of −1.58 V, a melt containing 1.3 wt% UCl3 and 1.5 wt% MoCl3 resulted in the co-electrodeposition of dendrites due to the high overpotential for Mo electrodeposition. However, diffusion-controlled electrodeposition using the same potential and concentration resulted in a uniform and flat U-Mo film. This co-electrodeposition of U-Mo films could be applied to the preparation of low-cost U-Mo nuclear fuel.