Effect of CeO2 and graphite powder on the electrochemical performance of Ti/PbO2 anode for zinc electrowinning

In the zinc hydrometallurgy process, the key to reduce the voltage of the corrosion is to reduce the oxygen evolution potential of the anode. In this experiment, the effects of doped CeO2 and graphite powder (GP) on the electrochemical properties of Ti/PbO2 were investigated. Ti/PbO2, Ti/PbO2-CeO2, Ti/PbO2-GP and Ti/PbO2CeO2-GP anode were prepared by direct current (DC) plating. The surface morphology and composition of these different Ti/PbO2 electrodes before and after polarisation were analysed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The corrosion mechanism was analysed by linear sweep voltammetry (LSV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), The cell voltage, current efficiency, service life and failure mechanism of Ti/PbO2 anodes were observed and analysed by simulating electrowinning experiments. The results show that Ti/PbO2-CeO2-GP anodes is denser than other electrodes. Ti/PbO2-CeO2 (12 g/L)-GP (8 g/L) with the lowest anode potential is 1.5390 V. The potential of the lowest oxygen evolution peak of the Ti/PbO2-CeO2 (12 g/L)-GP (8 g/L) electrode is 0.824 V. The Ti/PbO2-CeO2-GP anode had a minimum cell voltage of 2.85 V and a current efficiency of 95.8%. The Ti/PbO2-CeO2-GP has a minimum corrosion rate of - 0.0320 g.A(-1).h(-1) and a longest anode lifetime of up to 127 h. The best electrode for the surface coating is Ti/PbO2-CeO2 (12 g/L)-GP (8 g/L).