LiF-NaF-KF-K2TiF6-KBF4熔体中电沉积TiB2的阴极过程
来源期刊：中国有色金属学报2006年第6期
论文作者：李军 李冰
文章页码：1070 - 1075
关键词：二硼化钛；电化学还原；熔盐
Key words：titanium diboride; electrochemical reduction; molten salt
摘 要：采用循环伏安法研究了700 ℃时46.5LiF-11.5NaF-42KF（摩尔分数, %）熔盐中Ti(Ⅳ)（c(K2TiF6)=0.2 mol/L）和B(Ⅲ)（c(KBF4)=0.4 mol/L）在铂电极上的电化学还原机理, 计算了各还原步骤传递的电子数。 研究了LiF-NaF-KF-K2TiF6-KBF4（c(K2TiF4)=0.3 mol/L, c(KBF4)=0.3, 0.6, 0.9 mol/L）熔盐中电化学合成TiB2的阴极过程机理。 结果表明: Ti(Ⅳ)的电化学还原为三步电荷传递反应, 且阴极过程近似可逆； B(Ⅲ)在铂电极上的电化学反应机理为简单的三电子一步反应, 阴极过程近似可逆； Ti(Ⅳ)和B(Ⅲ)可在同一电位下发生共沉积并反应生成TiB2。
Abstract: The mechanism of the electrochemical reduction of Ti(Ⅳ) (c(K2TiF6)=0.2 mol/L) and B(Ⅲ) (c(KBF4)=0.4 mol/L) on the platinum electrode in 46.5LiF-11.5NaF-42KF (mole fraction, %) molten salt at 700 ℃ were investigated by means of the cyclic voltammetry technique. The cathode process of titanium diboride (TiB2) formation was also studied on the platinum electrode in the 46.5LiF-11.5NaF-42KF-K2TiF6-KBF4 (c(K2TiF4)=0.3 mol/L, c(KBF4)=0.3, 0.6, 0.9 mol/L)molten salt at 700 ℃. It is found that the electrochemical reduction of Ti(Ⅳ) proceeds in three-step charge transfer, the cathodic process is quasi-reversible. The electrochemical reduction of B(Ⅲ) occurs in one-step charge transfer, the cathodic process is quasi-reversible. The electrolytic codeposition of Ti(Ⅳ) and B(Ⅲ) with the formation of TiB2 can be achieved.
