A Study on Electrochemical Behaviors of Samarium Ions in the Molten LiCl-KCl Eutectic Using Optically Transparent Electrode

• Published in: Journal of nuclear fuel cycle and waste technology (Online) Vol. 15; no. 4; pp. 313 - 320
• Main Authors: Lee, Ae-Ri, Park, Byung Gi
• Format: Journal Article
• Language: English
• Published: 한국방사성폐기물학회 15.12.2017
• Subjects: 원자력공학
• ISSN: 1738-1894; 2288-5471
• DOI: 10.7733/jnfcwt.2017.15.4.313

A spectroelectrochemical method has been applied to investigate the electrochemical behaviors and identify the kinds of samarium ions dissolved in high temperature molten LiCl-KCl eutectic. An optically transparent electrode (OTE) fabricated with a tungsten gauze as a working electrode has been used to conduct cyclic voltammetry and potential step chronoabsorptometry. Based on the reversibility of the redox reaction of Sm3+/Sm2+ , which was determined from the cyclic voltammograms, the formal potential and the diffusion coefficient were calculated to be -1.99 V vs. Cl2/Cl- and 2.53 × 10-6 cm2·s-1, respectively. From the chronoabsorptometry results at the applied potential of -1.5 V vs. Ag/AgCl (1wt%), the characteristic peaks of absorption for samarium ions were determined to be 408.08 nm for Sm3+ and 545.62 nm for Sm2+. Potential step chronoabsorptometry was conducted using the anodic and the cathodic peak potentials from the voltammograms. Absorbance analysis at 545.63 nm shows that the diffusion coefficient of Sm3+ is 2.15 × 10-6 cm2·s-1, which is comparable to the value determined by cyclic voltammetry at the same temperature. KCI Citation Count: 1