摘要
在Pb-0.3%Ag合金基体表面制备了Pb-0.3%Ag/Pb-Co_3O_4复合惰性阳极材料,研究了不同正向脉冲平均电流密度(2-5A·dm^(-2))和镀液中Co_3O_4颗粒浓度(10-40 g/L)下制备的复合惰性阳极材料电化学性能,在50 g·L^(-1)Zn^(2+),150 g·L^(-1)H_2SO_4,35℃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3 A/dm^2正向脉冲平均电流密度和30 g/LCo3O4颗粒浓度下制备的Pb-0.3%Ag/Pb-Co_3O_4复合惰性阳极材料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500 A/m^2测试电流密度下的析氧过电位为0.891 V,比Pb-1%Ag合金降低280 mV;伏安电荷q~*为0.725 C·cm^(-2),比Pb-1%Ag合金提高26.5%;腐蚀电流也明显低于Pb-1%Ag合金。复合惰性阳极材料活性表面积大,活性物质数量多提高了在[ZnSO_4+H_2SO_4]溶液中的析氧电催化活性。沉积层晶粒细小而均匀,组织结构致密,真实表面缺陷少提高了耐腐蚀性。
Pb–0.3%Ag/Pb–Co3O4 composite inert anodes were prepared on the surface of Pb–0.3%Ag substrates, the electrochemical properties of the composite inert anodes obtained under different forward pulse average current densities from 2 A/dm^2 to 5 A/dm^2 and different Co3O4 concentrations from 10 g/L to 40 g/L in bath were investigated. The anodic polarization curves, cyclic voltammetry curves and Tafel polarization curves were measured in a synthetic zinc electrowinning electrolyte of 50 g/L Zn^2＋ and 150 g/L H2SO4 at 35℃, the kinetic parameters of oxygen evolution, voltammetry charge, corrosion potential and corrosion current were obtained. The results show that Pb–0.3%Ag/Pb–Co3O4 composite inert anode obtained under forward pulse average current density of 3 A/dm^2 and Co3O4 concentration of 30 g/L in bath, possess higher electrocatalytic activity, lower overpotential of oxygen evolution, better reversibility of electrode reaction and corrosion resistance in a synthetic zinc electrowinning electrolyte. The overpotential of oxygen evolution of the composite inert anode is 0.891 V under 500 A/m^2, and it is 280 mV lower than that of Pb–1%Ag alloy; the surface voltammetry charge q^＊ is 0.725 C·cm^-2, and is 26.5% higher than that of Pb–1%Ag alloy; the corrosion current is also lower than that of Pb–1%Ag alloy. Large active surface areas and active substance numbers on the surface of the composite inert anode improve the electrocatalytic activity for oxygen evolution in [ZnSO4＋H2SO4] solution. Fine and uniform grains, compact microstructures and fewer surface defects increase the corrosion resistance of the composite inert anode.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2012年第5期495-502,共8页
Chinese Journal of Materials Research
基金
国家自然科学基金51004056
中国科学院特种无机涂层重点实验室开放基金KKZ6201152009资助项目~~
作者简介
To whom correspondence should be addressed:徐瑞东,Tel:(0871)5161278,E-marl:rdxupaper@yahoo.com.cn
