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 β-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 β-PbO₂ coating. The electrochemical performance of the Al/TiB₂/β-PbO₂ and Ti/β-PbO₂ composites was studied by linear sweep voltammetry (LSV), Tafel polarization curves (Tafel) and electrochemical impedance spectroscopy (EIS). The results indicate that Al/TiB₂/β-PbO₂ composite electrode materials with a uniform structure 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 × 10⁷ S m⁻¹, and the optimal value of density is 8.758 g cm⁻³ for β-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/β-PbO₂ exhibited the best corrosion-resistant performance and electrochemical catalytic activity for electrowinning of nonferrous metals.