铜在低电导溶液中扩散机理的研究

The cause of Warburg impedance on the impedance spectra for copper electrode in low-conductivity solution has been studied. The slopes of Randles plots (Warburg coefficients) do not change with dissolved oxygen concentration and strring rate, but they increase with the increase of the pH of solution and driesion time. The experimental results show that the Warburg twedance at low frequencies is caused by the diffusion of copper ions from the inner side to the outer side of the oxide film on the surface of copper electrode.

低电导率溶液的EIS谱研究

对紫铜、1 8- 8不锈钢、2 0号碳钢 3种材料在一系列低电导率溶液中的 EIS谱进行了分析和研究。结果表明 :金属在低电导率溶液中的 EIS谱 ,高频部分都将出现一容抗弧 ,且随电导率升高 ,此容抗弧逐渐缩小 ;当电导率增到一定程度 ,高频容抗弧消失。由此高频容抗弧拟合出的电阻的倒数与溶液的电导率成线性关系 ,且不受电极腐蚀行为等的影响 ,表明此高频容抗弧系工作电极与参比电极间的溶液欧姆降电阻在溶液电导率极低时形成的 。