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采用循环伏安曲线(CV)和电化学交流阻抗谱(EIS)研究Pb-0.8%Ag和Al/Pb-0.8%Ag阳极在最初24 h锌电积过程中的阳极行为和析氧动力学。结果表明:2种阳极材料在阳极极化过程中的阳极行为和动力学的多种变化表明阳极表面膜的形成和稳定。与传统的Pb-0.8%Ag阳极相比,Al/Pb-0.8%Ag阳极具有较长的极化时间。在最初的电积过程中,阳极表面中间产物的转变使2种阳极都表现出较高的析氧电位。随着析氧电位降低,析氧反应速率可以由阳极表面最初的生成物和中间产物S-OHads推断。随着电积的持续进行,Al/Pb-0.8%Ag阳极的析氧电位逐渐降低,Al/Pb-0.8%Ag阳极比Pb-0.8%Ag阳极先达到稳定状态。电积24 h后,阳极电位由阳极表面的生成物和中间产物控制。采用扫描电子显微镜观察Al/Pb-0.8%Ag和Pb-0.8%Ag阳极锌电积24 h后的微观形貌。
The anodic behavior and oxygen evolution kinetics of Pb-0.8% Ag and Al / Pb-0.8% Ag anodes during the first 24 h of zinc electrowinning were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) The results show that the changes of anode behavior and kinetics during the anodic polarization of the two kinds of anode materials indicate the formation and stabilization of the anode surface film. Compared with the traditional Pb-0.8% Ag anode, Al / Pb-0.8% Ag anode has a longer polarization time. During the initial electrowinning process, the transition of the intermediate surface of the anode surface showed a higher oxygen evolution potential for both anodes. With the reduction of oxygen evolution potential, the oxygen evolution reaction rate can be deduced from the initial product of the anode surface and the intermediate product S-OHads. The oxygen evolution potentials of Al / Pb-0.8% Ag anodes decreased gradually with the increase of the electric potential, and the Al / Pb-0.8% Ag anodes reached a steady state before Pb-0.8% Ag anodes. After electrowinning for 24 h, the anodic potential was controlled by the product of the anode surface and the intermediate product. Scanning electron microscopy was used to observe the morphology of Al / Pb-0.8% Ag and Pb-0.8% Ag anodic zinc electrowinning for 24 h.