(152551)Ag doping to boost the electrochemical performance and corrosion resistance of Ti/Sn-Sb-RuO_x/α-PbO_2/β-PbO_2 electrode in zinc electrowinning

摘要

Ag doped β-PbO_2 anode material was prepared on Ti/Sn-Sb-RuO_x/α-PbO_2 through electrodeposition technique to improve its electrochemical properties and corrosion resistance in zinc electrowinning. The chemical composition and surface morphology of the anodes were characterized by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. The electrochemical properties and corrosion resistance of the anode materials were established via linear sweep voltammetry, cyclic vol-tammetry, electrochemical impedance spectroscopy and accelerated life tests. Results showed that the grain size of β-PbO_2 increased with AgNO_3 concentration while Ag~+ was oxidized to AgO and adsorbed on the electrode surface to accelerate the growth of β-PbO_2 grains. We also proposed the nucleation/ deposition mechanism of β-PbO_2 electrode while verifying the role of Ag ion doping. The optimum electrocatalytic performance could be achieved when the concentration of AgNO_3 was 6g L~(-1). Compared with that of the undoped pure β-PbO_2 anode, the oxygen evolution potential of the Ti/Sn-Sb-RuO_x/α-PbO_2/Ag-F-β-PbO_2 was decreased by 64 mV. The service life of the doped F-Ag-β-PbO_2 anode could reach up as high as 249 h, which was 1.66 times of pure β-PbO_2 anode.