铝棒低银铅合金表面陶瓷化复合阳极的制备与性能

为获得一种锌电积用低成本、低析氧电位和高催化活性的阳极，在铝棒表面通过挤压复合技术包覆Pb-0.2% Ag合金得到Al棒Pb-0.2% Ag阳极.在含氟的硫酸溶液中，通过阳极氧化在Pb-0.2% Ag合金和Al棒Pb-0.2% Ag合金阳极表面形成具有高催化性能的膜层，采用显微图像分析仪和数显显微硬度计表征了膜层的厚度及硬度，并通过电子拉伸试验对比了两种阳极的极限抗拉强度.采用X射线衍射、扫描电子显微镜、循环伏安法、阳极极化和交流阻抗法等技术手段研究了Al棒Pb-0.2% Ag与Pb-0.2% Ag阳极表面氧化膜层的物相、形貌以及电化学性能.结果表明:Al棒Pb-0.2% Ag阳极相比Pb-0.2% Ag阳极表面易生成致密较厚的氧化膜层，且膜层硬度提升了41.64%，其氧化膜层主要物相均为电催化活性良好的β-PbO₂.新型阳极的极限抗拉强度是传统阳极的1.3倍，大大改善了阳极材料的机械性能.阳极极化曲线数据显示Al棒Pb-0.2% Ag/PbO₂阳极在电积锌体系中具有较低的析氧电位(1.35 V vs MSE，500 A·m-2)和较高的交换电流密度(7.079×10-5 A·m-2).循环伏安曲线和交流阻抗数据显示Al棒Pb-0.2% Ag/PbO₂阳极具有较高的电催化活性、较大的表面粗糙度和较小的电荷传质电阻.在电积锌实验中，栅栏型Al棒Pb-0.2% Ag/PbO₂阳极相比传统Pb-0.2% Ag阳极平均槽电压下降了75 mV，而且大大减少了阳极泥的产生. 

Preparation and properties of Al-rod-Pb-0.2%Ag composite anode by surface ceramization

To obtain a low-cost anode with low oxygen evolution potential and high catalytic activity for zinc electrowinning, Pb-0.2%Ag alloy was coated on an aluminum matrix surface by extrusion cladding technology, and a film layer with high catalytic performance was formed on the surface of the Pb-0.2%Ag alloy and Al-rod-Pb-0.2%Ag anode by anodization in a fluorine-containing sulfuric acid solution. The thickness and hardness of the film were studied using a microscopic image analyzer and digital microhardness tester, and the ultimate tensile strengths of the two anodes were compared using an electronic tensile tester. The phase, morphology, and electrochemical performance of the Al-rod-Pb-0.2%Ag and Pb-0.2%Ag anode surface film were investigated using X-ray diffractometry, scanning electron microscopy, cyclic voltammetry, anodic polarization, and electrochemical impedance spectroscopy. The results show that the Al-rod-Pb-0.2%Ag anode surface forms a dense and thick oxide film layer more easily than the Pb-0.2%Ag anode and the hardness of the film layer is increased by 41.64%; moreover, the main phase is β-PbO₂, and the oxide film layer exhibits good electrocatalytic activity. The ultimate tensile strength of the new anode was 1.3 times that of the traditional anode, which greatly improves the mechanical properties of the anode material. Analytical data of anodic polarization curves reveal that the Al-rod-Pb-0.2%Ag/PbO₂ anode shows low oxygen evolution potential (1.35 V vs MSE, 500 A·m-2) and high exchange current density (7.079×10-5 A·m-2) in zinc electrowinning system. Analytical data of cyclic voltammetry and EIS curves indicate that the Al-rod-Pb-0.2%Ag/PbO₂ anode has higher electrocatalytic activity, larger surface roughness, and smaller charge transfer resistance. In the zinc electrowinning experiment, the average cell voltage of the fence-like Al-rod-Pb-0.2%Ag/PbO₂ anode was 75 mV less than that of the traditional Pb-0.2% Ag anode, and the production of anode slime was greatly reduced.