不同氯化锰含量对铁电沉积过程的影响  

Effect of Manganese Chloride Content on Cathodic Process of Iron Electrodeposition

作　　者：田永常[1] 方小红[1] 潘秉锁[1] 杨凯华[1] 

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074

出　　处：《材料保护》2014年第6期9-12,6,共4页Materials Protection

基　　金：中央高校基本科研业务费专项资金(CUGL130211)资助

摘　　要：过去,鲜见氯化锰对铁电沉积阴极过程影响的报道,对铁沉积机理研究相对较少。采用线性扫描伏安法、单电位阶跃计时电流法、交流阻抗谱等技术对基础镀铁液和加入氯化锰后的镀铁液中铁在玻碳电极上的电沉积进行了对比性研究。结果表明:加入氯化锰增大了阴极电化学极化,并有效降低了浓差极化,氯化锰含量超过34g/L后提高含量对阴极极化影响不明显;在-1.225^-1.300 V阶跃电位内,不管镀液中是否含有氯化锰,铁在玻碳电极上的电结晶都遵循三维瞬时成核理论,添加氯化锰后扩散系数D显著升高,添加50 g/L MnCl2镀液中的扩散系数相对于基础镀液涨幅达74%;氯化锰使溶液/电极界面电荷传递电阻Rct显著提高、溶液电阻Rsol呈小幅度降低,双电层电容Cdl显著增大,与阴极极化结果相吻合。Linear sweep voltammetry,single-potential step chronoamperometry and alternating current electrochemical impedance spectroscopy were employed to comparatively study the electrocrystallization behavior of iron in basic solution and solutions containing MnCl_2.Results showed that the addition of MnCl_2increased the cathodic electrochemical polarization and decreased the concentration polarization effectively,but further increasing MnCl_2 concentration above 34 g/L caused insignificant change in the effect on the cathodic process.In the step-voltage range of-1.225^-1.300 V,the electrocrystallization of iron on glassy carbon electrode followed three dimensional instantaneous nucleation whether the electrolyte contained MnCl_2 or not,while the addition of 50 g/L MnCl_2 increased the diffusion coefficient of Fe^(2+) by up to 74%as compared to that in the basic solution.Moreover,the addition of MnCl_2 increased the charge transfer resistance at the metal/electrolyte interface and the capacitance of electric double layer and decreased the solution resistance,which was consistent with relevant cathodic polarization results.

关 键 词：铁电沉积 氯化锰 成核机理 交流阻抗 

分 类 号：TQ153[化学工程—电化学工业]