锌电极电化学行为研究(Ⅶ)——碱性电解液中汞齐化锌电极的恒相角行为

利用电化学交流阻抗法对锌盘及汞齐化锌盘电极在碱性电液中的电化学行为进行比较研究时,发现汞齐化锌电极在很宽的频率范围内呈现恒相角行为(constant phase element),以分形理论及分形维数对锌电极汞齐化前后的阻抗谱数据进行了分析,结果表明锌电极表面是一个分形表面,汞齐化改善了电极的表面状况,即其表面的分形性质,使其粗糙度下降,从而使分形维数减小,最后成为光滑的平面电极,此时界面无法拉第过程,界面的阻抗行为较为简单.锌电极的阻抗行为是与表面汞齐化前后的分形维数紧密相关的,可通过汞齐化研究如何控制固体电极粗糙度及分形电极表面分形性质的变化.

CPE behavior of amalgamation zinc electrode in alkaline electrolyte

The AC impedance responses of zinc disk and amalgamation zinc disk electrodes in alkaline electrolyte were investigated by the electrochemical impedance spectroscopy(EIS) technique. It was found that the impedance responses of amalgamation zinc disk electrode were consistent with the constant phase element (CPE) form in very wide frequency range. According to the fractal theory,the change of the fractal dimension with the time of amalgamation were calculated for amalgamation zinc disk electrode. The study shows that the amalgamation is a method of studying how to control the roughness of solid electrode and the changes of fractal properties at the surface of electrode.