尿素对甲酸盐体系三价铬电沉积的作用机理  

Mechanism of the effect of urea on electrodeposition of trivalent chromium from Cr(III)–formate plating system

作　　者：李烨[1] 高云芳[1] 徐新[1] 姚秋实[1] 

机构地区：[1]浙江工业大学化学工程与材料学院,浙江杭州310014

出　　处：《电镀与涂饰》2013年第9期5-8,共4页Electroplating & Finishing

摘　　要：采用紫外–可见分光光度法(UV–vis)和电化学分析法研究了尿素对Cr(III)–甲酸盐镀液体系电沉积过程的作用机理。UV–vis谱图表明,尿素可参与Cr(III)–甲酸盐镀液体系的配位取代反应。线性扫描伏安曲线和恒电位电沉积试验表明,尿素可提高Cr(III)–甲酸盐体系中铬的沉积过电位,并抑制析氢反应。不同配位体系所得镀层的表面形貌表明,尿素可细化Cr(III)–甲酸盐镀液体系电沉积铬的晶核。The mechanism of the effect of urea on electrodeposition of chromium from a Cr（Ⅲ）--formate electrolyte was studied by ultraviolet-visible （UV-vis） spectrophotometry and electrochemical analysis. UV-vis spectra show that urea takes parts in the complex substitution in Cr（Ⅲ）-formate plating bath. Linear sweep voltammetric curves and potentiostatic electrodeposition test indicate that urea can raise the deposition overpotential of chromium in Cr（Ⅲ）-formate plating system and inhibit hydrogen evolution. Surface morphologies of the coatings prepared from plating baths with different complexing agents show that chromium grains can be refined by urea in Cr（Ⅲ）-formate plating system.

关 键 词：三价铬 电沉积 尿素 配位剂 电化学 机理 

分 类 号：TQ153.11[化学工程—电化学工业]