采用双脉冲电沉积,在Pb-0.3%Ag(质量分数,下同)合金基体表面制备了Pb-0.3%Ag/Pb-CeO2复合阳极材料,研究了不同正向脉冲平均电流密度(2~5 A·dm-2)和镀液中CeO2颗粒浓度(0~20 g/L)下制备的复合阳极材料电化性能,在50 g·L-1 Zn2+,150 g·L-1 H2SO4,35℃溶液中测试了阳极极化曲线、循环伏安曲线和塔菲尔曲线,获得了析氧动力学参数、伏安电荷、腐蚀电位和腐蚀电流。结果表明:在正向脉冲平均电流密度为3 A/dm2和镀液中CeO2颗粒浓度为15 g/L下制备的Pb-0.3%Ag/Pb-CeO2复合阳极材料在[ZnSO4+H2SO4]溶液中具有较高的电催化活性,较低的析氧过电位,较好的电极反应可逆性和耐腐蚀性。在[ZnSO4+H2SO4]溶液中,复合阳极材料在测试电流密度500 A/m2下的析氧过电位为1.134V,比Pb-1%Ag合金降低37 mV;腐蚀电流为1.97×10-4 A,明显低于Pb-1%Ag合金,表现出了良好的耐腐蚀性能。
Pb-0.3%Ag/Pb-CeO2 composite anodes were prepared by double-pulse electrodeposition on the surface of Pb-0.3%Ag (mass fraction) substrates. The electrochemical properties of the composite anodes obtained under different forward pulse average current densities from 2 to 5 A/dm2 and different CeO2 concentrations from 0 to 20 g/L in bath were investigated, the anodic polarization curves, cyclic voltammetry curves and Tafel polarization curves in a synthetic zinc electrowinning electrolyte of 50 g/L Zn2+ and 150 g/L H2SO4 at 35 ℃ were measured, and the kinetic parameters of oxygen evolution, voltammetry charge, corrosion potential and corrosion current of the composite anodes were obtained. The results show that Pb-0.3%Ag/Pb-CeO2 composite anodes obtained under forward pulse average current density of 3 A/din2 and CeO2 concentrations of 30 g/L in an original acid plating bath, possess higher electrocatalytic activity of oxygen evolution, lower overpotential of oxygen evolution, better reversibility of electrode reaction and corrosion resistance in [ZnSO4+H2SO4] solution. The overpotential of oxygen evolution of the composite anode is 1.134 V under 500 A/m2 in [ZnSO4+H2SO4] solution, and 37 mV lower than that of Pb-l%Ag alloy; the corrosion current of the composite anode is 1.97×104A which is distinctly lower than that of Pb-l%Ag alloy, showing excellent corrosion resistance.