Electrochemical Reactions of Uranium Trichloride on a Graphene Surface in LiCl-KCl Molten Salt

Abstract

The electrochemcal reactions of uranium trichloride on the surfaces of dimensionally very dissimilar carbon-based materials such as glassy carbon (GC) and graphene in LiCl-KCl eutectic melt were investigated using cyclic voltammetry (CV) and scanning electron microscopy (SEM). The cathodic scanning of CV displayed that the Li intercalation reaction into the GC electrode governs at the potential of approximately −1.45 V vs. Ag|Ag + where the electrodeposition reaction of uranium may occur. On the other hand, the graphene electrode presented electrodeposition current of the uranium without interference at −1.45 V vs. Ag|Ag + because the Li intercalation reaction was extensively diminished on the very thin graphene film. In addition, it was successful to measure the electrodeposition current of gadolinium at more positive than −2.1 V without the interference of the Li intercalation into the graphene substrate. Consequently, the significant reduction of the Li intercalation reaction on the nanometer thick carbon electrode extensively expands the electrochemical potential window of the carbon-based electrode with respect to the bulk carbon electrode in LiCl-KCl melt, emphasizing that the graphene has a great potential as a cathode electrode in high temperature molten salt electrolytes.

Investigation of the Electrochemical Behavior of Ytterbium Cations in LiCl-KCl Melt Using Spectro-Electrochemical Methods

“…Recently pyrochemical processes have attracted significant attention, particularly in the context of recycling spent nuclear fuel. [1][2][3][4] Such pyrochemical processes concern a variety of elements associated with the spent nuclear fuel; 5 most of the uranium is collected in an electro-refining process, 6,7 whereas residual uranium, transuranium (TRU), and lanthanide ions are gathered in an electro-winning process. 8 The TRU and lanthanide elements are reduced at the liquid cadmium cathode, while counter oxidation reactions such as Cl 2 evolution, the oxidation of U 3+ , etc.…”

Electrochemical and Raman Spectroscopic Investigations on the Speciation and Behavior of Chromium Ions in Fluoride Doped Molten LiCl-KCl

“…36 The observation of such shift should be due to the formation of insoluble products such as metallic chromium in this case. 37,38 It is worth noting that the anodic peak current A 2 is not linearly correlated with ν 1 / 2 , which is different from the case of the corresponding cathodic current. Similar deviations have been observed for the anodic behaviors of uranium in LiCl-KCl.…”

Electrochemical preparation and spectroelectrochemical study of neptunium chloride complexes in LiCl–KCl eutectic melts

“…[22] at 450°C, limiting the potential window of the melt between both reactions [9]. The anodic reactions of the Np species occurred at 0.47 and 0.94 V versus Ag|Ag ?…”

“…Thus, many electrochemical studies on actinide and lanthanide chloride complexes in molten chloride baths have been performed to elucidate the electrochemical behaviors of such nuclides [4]. In particular, many studies have focused on uranium [5][6][7][8][9] because the pyroprocess was developed primarily for recovering uranium from spent nuclear fuel. However, from the viewpoint of long-term radiotoxicity management of spent nuclear fuel waste, removing long half-life transuraniums (TRUs) from the processing salt bath after uranium recovery is also very important.…”