Preparation And Properties Of Three-dimensional Porous Structure PbO₂ Electrodes

The constant voltage electrodeposition method has been used in this paper.Growth rate of lead dioxide crystal and the quantities of oxygen bubble which generated by oxygen evolution reaction both can be controlled by changing voltage,so that the lead dioxide crystal can electro-deposit in the crack of the oxygen bubble template.Then we got the lead dioxide electrodes with three-dimensional porous structure,the reactivity surface area of lead dioxide electrodes have increased.According to this paper,the optimum process conditions for preparing the three-dimensional porous structure lead dioxide were determined as follows:react voltage was 5V,react times was 50s.Scanning electron microscopy（SEM）and X ray diffraction（XRD）analysis result show that the electrodes have a obvious porous structure.Compared with the flat structure lead dioxide electrodes these surface on electrodes are more smooth and well-distributed and the crystal size decrease sharply to 5.4nm.When the electrodes are in the 1mol/L Na₂SO₄ solution and at 100 mA/cm²current density then the oxygen evolution overpotential is 1.74V.The electrochemical activity surface area experiment show that the total surface area of these electrodes are 0.08099 C/cm² and the inner surface area of these electrodes are 0.07632 C/cm² as three times as the flat lead dioxide electrodes.The super-capacitor properties of the three-dimensional porous structure lead dioxide electrodes had investigated in this paper.When the electrodes in 0.5mol/L H₂SO₄ solution the cyclic voltammogram curves show that the oxidation peak and reduction peak of the three-dimensional porous structure lead dioxide electrodes are as three times as the flat electrodes.The electrochemical ac impedance spectrogram show that rhe semicircle of the three-dimensional porous structure lead dioxide electrodes are less than the flat one,its electron transfer resistance is 34.64?/cm².We had calculated the specific capacitance and specific energy by the constant current discharge curves.When the discharge current density is 1.0A/g the specific capacitance can reach 195.65 F/g.When the discharge current density is 0.2A/g the specific energy can reach 69.56Wh/kg.The optimal process conditions for electrochemical oxidation crystal violet had investigated in this paper,optimal process conditions were as follows:current density was 30 mA/cm²,initial concentration of crystal violet was 30mg/L,the initial pH was 4,concentration of electrolyte（Na2SO4）was 0.20mol/L.Under such operation condition,the color removal efficiency of crystal violet reached 95.72%,COD removal efficiency reaches 66.93%after 120 min.The kinetics study showed that crystal violet electrocatalysis degradation reaction followed with the-first-order kinetics...