Preparation And Electrochemical Performance Of Titanium-clad Aluminum-based PbO₂ Composite Anode Material By Pulse Electrodeposition

At present,the titanium-based PbO₂ anode is extensively studied in the galvanized zinc industry.The application of pure lead dioxide in electrocatalysis is seriously hindered by its high oxygen evolution potential in the electrolytic zinc solution.Therefore,the improvement of the electrocatalytic activity of lead dioxide has considerable significance.Based on the influence of the composition and microstructure of the lead dioxide electrode on its electrocatalytic performance.In this dissertation,the composite anode material doped by nano-ZrO₂ active particles for electrolytic zinc was obtained on the basis of the prepared titanium-based lead dioxide by changing the bath composition and process conditions.The research results obtained are as follows:In this paper,for the purpose of solving some defects of titanium-based PbO₂ electrode,such as large stress,easily peeling coating,A pulsed composite electrodeposition method was applied to prepare a Ti/Al/Ti/?-PbO₂-ZrO₂ composite electrode on square rod-shaped titanium coated aluminum surfaces.The effect of the average current density,pulse current duty cycle,pulse current frequency,ZrO2 addition amount on the electrocatalytic performance of Ti/Al/Ti/?-PbO₂-ZrO₂ composite electrode was investigated by scanning electrochemical microscopy?SEM?,X-ray diffraction?XRD?,anodic polarization curves?LSV?and Tafel curve test method?Tafel?,respectively.The optimum preparation process system of Ti/Al/Ti/?-PbO₂-ZrO₂ composite anode materials was determined by pulse composite electrodeposition.The results showed that the optimal preparation process conditions were:ZrO₂ concentration:10g/L,the pulse frequency was 20Hz,the duty ratio was 30%,and the average current density was31.25mA/cm².In this process,Ti/Al/Ti/?-PbO₂-ZrO₂ composite anode materials were prepared with a smooth and dense coating,and the grains were uniformly refined,and has better catalytic activity and corrosion resistance.When the anode composite material is used as an electrodeposited zinc anode,the influence of the addition amount of nano-ZrO₂ active particles on the number of active sites on the electrode surface is further studied through measurement and analysis of cyclic voltammograms and AC impedance.The electrode prepared after doping 10 g/L of nano-ZrO₂ particles has a smaller capacitance arc,which indicates that the oxygen evolution reaction in the electrolytic zinc solution has a smaller energy barrier,and the faster electrode reaction rate,higher electrocatalytic activity.Compared with undoped nano-ZrO₂ electrode material,the number of active sites on the surface of the electrode material added with 10 g/L nano-ZrO₂ increased by nearly twice.From the analysis of SEM and XRD,the doping of nano-ZrO₂ not only increases the physical surface area of the electrode material surface,but also increases the number of surface active sites of the electrode material,which provides more active sites for the oxygen evolution reaction.and essentially explain the deep reasons for the increase in electrocatalytic activity.The investigation of the bath by cyclic voltammogram?CV?and chronoamperometry?CA?confirms that the electrodeposition of PbO₂ in the presence of ZrO₂ is an irreversible process controlled by diffusion.According to the dimensionless j²/j_m²-t/t_m curve of electrodeposited PbO₂ process,the electrocrystallization of PbO₂ conforms to the three-dimensional Scharifker-Hill nucleation model under diffusion control.When the value of overpotential increases,the number of nucleation active sites increases.The nucleation relaxation time is shortened.