open access publication

Article, 2023

Direct electrochemical dissolution of metallic uranium into deep eutectic solvent

Journal of Nuclear Materials, ISSN 1873-4820, 0022-3115, Volume 575, Page 154229, 10.1016/j.jnucmat.2022.154229

Contributors

Yang, Wonseok 0000-0001-9716-9459 [1] [2] Jung, Chanyong [3] Cha, Han Lim 0000-0001-9045-3414 [1] Park, Jun Woo [1] Foster, Richard Ian 0000-0002-5807-6062 [2] Amphlett, James T M 0000-0002-0135-587X [1] [4] Liu, Shuang [2] Bae, Sang-Eun 0000-0003-2668-8950 [3] Yun, Jong-Il 0000-0001-8629-2259 [1] Choi, Sungyeol (Corresponding author) [2]

Affiliations

  1. [1] Korea Advanced Institute of Science and Technology
  2. [NORA names: South Korea; Asia, East; OECD];
  3. [2] Seoul National University
  4. [NORA names: South Korea; Asia, East; OECD];
  5. [3] Korea Atomic Energy Research Institute
  6. [NORA names: South Korea; Asia, East; OECD];
  7. [4] Seaborg Technologies, Titangade 11, 2200 Copenhagen N, Denmark
  8. [NORA names: Denmark; Europe, EU; Nordic; OECD]

Abstract

Deep eutectic solvents (DESs) could make uranium recycling processes greener than using conventional solvents, owing to their inherent advantages such as being biodegradable and non-toxic. However, the chemistry of uranium ions in DES systems, particularly the mechanism of direct anodic dissolution of uranium metal, remains unclear. The anodic dissolution of uranium metal in choline chloride (ChCl)–ethylene glycol (EG) DES was conducted by applying a constant current. The oxidation state of uranium in ChCl-EG DES was uranium(IV) when compared to concentration and applied charge. Absorption spectra showed 8 coordinated U(IV) centered complexes formed in the ChCl-EG DES, regardless of the uranium source (i.e. uranium chloride or metallic uranium anodic dissolution). The in situ spectroelectrochemistry during potentiostatic electrolysis, cyclic voltammograms, and absorption spectra of different times of potentiostatic electrolysis showed U(IV) oxidized to U(V), and then the U(V) disproportionated into U(IV) and U(VI) species. Understanding fundamental uranium speciation in DES systems and electrochemical properties could facilitate the development of an eco-friendly nuclear fuel cycle and nuclear uranium recycling process using green DESs.

Keywords

ChCl-EG, ChCl-EG deep eutectic solvents, EG, U(IV, U(V, U(VI) species, absorption, absorption spectra, anodic dissolution, charge, chemistry, choline, compared to concentrations, complex, concentration, constant current, conventional solvents, current, cycle, cyclic voltammograms, deep eutectic solvent system, deep eutectic solvents, development, electrochemical dissolution, electrochemical properties, electrolysis, eutectic solvents, fuel cycle, glycol, green deep eutectic solvent, in situ spectroelectrochemistry, ions, mechanism, metal, metallic uranium, non-toxic, nuclear fuel cycle, oxidation, oxidation state, potentiostatic electrolysis, process, properties, recycling process, solvent, source, speciation, species, spectra, spectroelectrochemistry, state, system, uranium, uranium ions, uranium metal, uranium source, uranium speciation, voltammograms

Funders

  • Korea Institute of Materials Science
  • National Research Foundation of Korea
  • Ministry of Science and ICT

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