Dy(Ⅲ)离子在LiCl-KCl熔盐中的电化学行为及Dy-Ni金属间化合物的选择性制备(英文)

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

采用循环伏安、方波伏安和开路计时电位等电化学方法研究了Dy(III)离子在Li Cl-KCl共晶盐中的电化学行为及Dy-Ni合金形成的电化学机理.循环伏安和方波伏安法研究表明,Dy(III)离子的电化学还原过程为三个电子转移的一步反应.与惰性W电极相比,Dy(III)离子在Ni电极上的循环伏安曲线多出了三对氧化还原峰,是由于Dy与Ni形成了合金化合物,导致Dy(III)离子在活性Ni电极发生了欠电位沉积.采用X射线衍射(XRD)和扫描电子显微镜(SEM)附带能量散射谱(EDS)对恒电位(-1.6,-1.8和-2.0 V)电解制备的Dy-Ni合金进行分析,分别获得了DyNi_5,Dy_2Ni_7和DyNi_2金属间化合物.实验结果表明,通过控制电位进行恒电位电解可以有选择性地制备不同的金属间化合物.

The electrochemical behavior of Dy（Ⅲ） in LiCI-KCI 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： DyNis, Dy2NiT, and DyNi2 can be selectively obtained by potentiostatic electrolysis at different potentials.