Preparation and electrochemical properties of Al/TiB2/β-PbO2 layered composite electrode materials for electrowinning of nonferrous metals

In this paper, an Al/TiB2 layered composite was prepared by plasma spraying for use as the base material to reduce resistivity and improve electrochemical performance in an electrode. The beta-PbO2 coating was prepared by electrochemical deposition. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to study the Al/TiB2 composite and the beta-PbO2 coating. The electrochemical performance of the Al/TiB2/beta-PbO2 and Ti/beta-PbO2 composites was studied by linear sweep voltammetry (LSV), Tafel polarization curves (Tafel) and _electrochemical impedance spectroscopy (EIS). The results indicate that Al/TiB2/beta-PbO2 composite electrode materials with a uniform struttute-were successfully_ prepared by plasma spraying and electrochemical deposition. The structure of the Al/TiB2 composite improves the conductivity of the electrode-matrix,-the optimal value of conductivity is 2.76 x 107 S m(-1), and the optimal value of density is 8.758 g cm(-3) for beta-PbO2 coating. The composite also decreases the charge resistance in the double layer structure of the electrode surface, accelerating the charge transfer rate. Compared with the Ti matrix, the Al/TiB2/beta-PbO2 exhibited the best corrosion-resistant performance and electrochemical catalytic activity for electrowinning of nonferrous metals.