Preparation And Properties Of PbO₂-ZrO₂Nanocomposite Electrodes

PbO₂-ZrO₂nanocomposite electrodes were prepared by electrodeposition method. Theinfluence of preparation conditions for the performance, the effect of ZrO₂nanoparticles in theelectrodeposition process and electrochemical properties for degradation ofp-chlorophenol（4-CP） for the nanocomposite electrode were researched in this paper.The SnO₂-Sb2O3interlayer deposited onto the preteated Ti plates was prepared by thermaldecomposition. The best preparation technological condition which determined by the contentof ZrO₂nanoparticles in the coating is6g/L of the ZrO₂2nanoparticles,3A/dmof the currentdensity,180rpm of the stirring speed and bath temperature is30℃. Under those conditions, theservice life of the nanocomposite electrode can reach to144hours,4times longer than the purelead dioxide electrode. The SEM shown that surface of composite electrode more closelypacked and grain size smaller than the pure electrode. Besides, the XRD indicate that thecomposite electrode is mainly composed of β-PbO₂and the grain size calculated by Scherrerformula find that decrease from16.7nm to12.1nm. The electrochemical activity of totalsurface charge for composite electrode is2times higher than the pure electrode and higheroxygen evolution potential which helpful for the degradation of organic pollutants.By using cyclic voltammetry（CV） and chronoamperometry（CA） to research the effect ofZrO₂namoparticles for the lead dioxide electrodeposition process, which is an instantaneousnucleation and three-dimensional growth process and same to the Scharifker-Hills model. Thekinetic parameters of electrodeposition which calculate from polarization curve show that thedeposition process is mainly controlled by diffusion. The result of electrochemical impedancespectroscopy（EIS） and impedance potential（IMPE）for add nano-ZrO₂indicate the nano-ZrO₂particle play a role of inhibition in the electrodeposition process of lead dioxide.The removal rate of COD was used to obtain the optimal degradation conditions forp-chlorophenol（4-CP） of the nanocomposite electrode. Under the condition of initialconcentration8mmol/L, current density200mA/cm2, H2SO4concentration0.5mol/L, pH6.5to degradation the p-chlorophenol（4-CP） for6hours, the removal rate reached to89.2%.Besides, the instantaneous current efficiency for the nanocomposite electrode is higher than thepure electrode. In the solution of0.5mol/L H2SO4and8mmol/L4-CP, cyclic voltammetry（CV）show that the compoeite electrode has good catalytic activity and the ability of regeneration,furthermore the degradation reaction controlled by diffusion.