(1.山东矿业学院材料工程研究所 泰安 271019;
2.北京科技大 学理化系， 北京 100083)
摘 要: 通过吸光度测量和示波极谱等方法研究了不同来源的Cr3+在不同介质中的配合离子存在形态。结果表明， 新还原得到的Cr(Ⅲ)主要以[Cr(H2O)6]3+形式存在于溶液中，而普通CrCl3·6H2O中Cr(Ⅲ)的具体形态为较难还原的[Cr(H2O)4?/FONT>Cl2]+。介质pH值发生变化时, Cr (Ⅲ)的存在形式也随之变化，由pH<3时的[Cr(H2O)6]3+逐渐转变为pH>3时的[Cr(H2O)5OH]2+，还原电位随之负移。 因此， 为了保证Cr(Ⅲ)阴极过程的顺利进行， 应尽量保持镀液中的Cr3+以[Cr(H2O)6]3+的形式存在。
关键字: 电镀铬 三价铬 阴极过程 配合物
（1.Shandong Institute of Mining and Technology, Tai'an 271019, P. R. China;
2.University of Science and Technology Beijing, Beijing, 100083 P. R. China）
Abstract:The species of Cr3+ complex-ion coming from different source in different media have been investigated by means of measurement of light absorptivity and oscillographic polarography. The results showed that the freshly-reduced Cr(III) exists mainly as [Cr(H2O)6]3+ in the solution, while the species of Cr(III) in common CrCl3·6H2O is [Cr(H2O)4Cl2]+ reduced more difficultly; when pH value of the medium changes, the species of Cr(III) changes gradually from [Cr(H2O)6]3+ at pH<3 to [Cr(H2O)5OH]2+ at pH>3 and the reducing potential shifts negatively. To ensure cathodic reduction of Cr(III) to be proceeded smoothly, one should make efforts to keep Cr3+?in the bath to exist as Cr(H2O)6]3+.
Key words: chromium electroplating trivalent chromium cathodic reduction complex.
