Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (2): 309-314.doi: 10.3866/PKU.WHXB201412182

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Electrochemical Behavior of Dy(Ⅲ) and the Selective Formation of Dy-Ni Intermetallic Compounds in LiCl-KCl Eutectic Melts

LI Mei1, SUN Ting-Ting2, LIU Bin1, HAN Wei1, SUN Yang1, ZHANG Mi-Lin1   

  1. 1. Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, P. R. China;
    2. Department of Construction Engineering, Qiqihar Institute of Engineering, Qiqihar 161005, Heilongjiang Province, P. R. China
  • Received:2014-10-27 Revised:2014-12-17 Published:2015-01-26
  • Contact: HAN Wei E-mail:weihan@hrbeu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21271054, 21173060), Major Research Plan of the National Natural Science Foundation of China (91326113, 91226201), and Fundamental Research Funds for the Central Universities, China (HEUCF201403001).

Abstract:

The electrochemical behavior of Dy(Ⅲ) in LiCl-KCl melts and the alloying mechanism of Dy-Ni alloys were investigated by cyclic voltammetry, square wave voltammetry, and open circuit chronopotentiometry. Cyclic voltammetry and square wave voltammetry experiments indicated that the reduction of Dy(Ⅲ) ions to Dy metal occurred in a single step with the exchange of three electrons. Compared with cyclic voltammograms on an inert W electrode, three reduction peaks are observed. This indicates the under-potential deposition of Dy(Ⅲ) on a reactive Ni electrode because of the formation of Dy-Ni alloy compounds. Dy-Ni alloys were prepared by potentiostatic electrolysis at -1.6, -1.8, and -2.0 V and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectrometry (EDS). The results confirm that different Dy- Ni compounds: DyNi5, Dy2Ni7, and DyNi2 can be selectively obtained by potentiostatic electrolysis at different potentials.

Key words: Dy-Ni intermetallic compound, Electrochemical behavior, Molten chloride, Potentionstatic electrolysis, Ni electrode