摘要
We prepared Pb-0.3wt%Ag/Pb-WC（WC stands for tungsten carbide,the same below） composite inert anodes by double-pulse electrodeposition on the surface of Pb-0.3wt%Ag substrates,and investigated the electrochemical properties of the composite inert anodes,which were obtained under different forward pulse average current densities from 2 A/dm2 to 5 A/dm2 and WC concentrations from 0 g/L to 40 g/L in bath.The kinetic parameters of oxygen evolution,corrosion potential and corrosion current of the composite inert anodes were obtained in a synthetic zinc electrowinning electrolyte of 50 g/L Zn2＋ and 150 g/L H2SO4 at 35 ℃,by measuring the anodic polarization curves,Tafel polarization curves and cyclic voltammetry curves.The results show that Pb-0.3wt% Ag/Pb-WC composite inert anodes obtained under forward pulse average current density of 3 A/dm2 and WC concentration 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 inert anode is 0.926 V under 500 A/m2 in [ZnSO4＋H2SO4] solution,and 245 mV lower than that of Pb-1% Ag alloy;the corrosion current of the composite inert anode is 0.95×10-4A which is distinctly lower than that of Pb-1%Ag alloy,showing the excellent corrosion resistance.
We prepared Pb-0.3wt%Ag/Pb-WC（WC stands for tungsten carbide,the same below） composite inert anodes by double-pulse electrodeposition on the surface of Pb-0.3wt%Ag substrates,and investigated the electrochemical properties of the composite inert anodes,which were obtained under different forward pulse average current densities from 2 A/dm2 to 5 A/dm2 and WC concentrations from 0 g/L to 40 g/L in bath.The kinetic parameters of oxygen evolution,corrosion potential and corrosion current of the composite inert anodes were obtained in a synthetic zinc electrowinning electrolyte of 50 g/L Zn2＋ and 150 g/L H2SO4 at 35 ℃,by measuring the anodic polarization curves,Tafel polarization curves and cyclic voltammetry curves.The results show that Pb-0.3wt% Ag/Pb-WC composite inert anodes obtained under forward pulse average current density of 3 A/dm2 and WC concentration 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 inert anode is 0.926 V under 500 A/m2 in [ZnSO4＋H2SO4] solution,and 245 mV lower than that of Pb-1% Ag alloy;the corrosion current of the composite inert anode is 0.95×10-4A which is distinctly lower than that of Pb-1%Ag alloy,showing the excellent corrosion resistance.
基金
Funded by the Specialized Research Fund for the Doctoral Program of the Ministry of Education of China(No.20125314110011)
the Key Project of Yunnan Province Applied Basic Research Plan of China(No.2014FA024)
the National Natural Science Foundation of China(No.51564029)
