| Electrode, which is the core in electrochemical reaction system, is the key factors thatdetermine electrode properties. In the process of electrolysis,the reduction reaction occuredin cathode,and it has greater degrees of freedom for the choice of cathode materials.Whilethe oxidation reaction is happened in anodic, the reaction conditions are generally moreharsh, and anode materials are generally easy to wear and tear. Therefore, choosing efficientand stable anode electrode material is the focus of current research. In numerous anodematerial, lead dioxide electrode for high oxygen evolution potential, good corrosionresistance and relatively low price advantages, is widely used in the fieldof electrochemical synthesis and degradation of organic pollutants.This paper, using the pulse electroplating technology in the lead nitrate solutionadding the ZrO2nanoparticles, optimize the traditional dc lead dioxide electrode. Examinesthe impact of pulse parameters and the amount of ZrO2nanoparticles composite coating.According to single factor experiment, the optimum process conditions were determined:ZrO2nanoparticles concentration of6g/L, pulse frequency of10Hz, the duty ratio of0.2,the current density of75mA/cm2, Under those conditions, ZrO2particles content in theelectrode is the highest, up to7.2%(wt%). Scanning electron microscopy (SEM) resultsshow that, the pulse electroplating PbO2-ZrO2nano composite electrode surface roughnessand grain is fine. X ray diffraction (XRD) show that, pulse electrodeposition ofPbO2-ZrO2nano composite electrode are pyramid structure, the grain size is8.7nm.Electrochemical tests show that in1mol/L H2SO4solution, the optimal preparationconditions of the oxygen evolution potential is moved, electrochemical performance wasimproved.The service life of PbO2-ZrO2nanocomposite electrodes in2mol/L sulfuric acidsolution reaches298h.which is4times longer than that of pulse electrodeposition PbO2electrodes,2times that of direct current lead dioxide composite electrode.With the rapid development of printing and dyeing industry, a large number of dyewaste water discharge into the environment,has become one of the serious problems in thefield of water treatment. Electriccatalytic oxidation technology for its stable, efficient, mildreaction conditions and environmental compatibility, become a research hotspot in recentyears.Based on pulse electrodeposition PbO2-ZrO2nanometer composite electrodes are theanode, electric catalytic degradation of methylene blue simulated wastewater.At the same time, the influence factors of methylene blue removal rate such as current density,initialmethylene blue concentration, supporting electrolyte Na2SO4concentration and pH valuewere investigated systematically. It was found that the optimal process conditionselectrochemical oxidation of MB were: initial concentration of methylene blue30mg/L,current density of50mA/cm2, the initial pH of3, concentration of electrolyte (Na2SO4)0.20mol/L. Under such operation condition, the degradation rate of methylene blue reached100%, COD reaches72.7%after120min.The kinetics study showed that methylene bluedegradation reaction accorded apparently with the-first-order kinetics.Polarization curves by the composite electrode in methylene blue solution ofdifferent scan rate, the oxidation peak current increases with the increase of the scanningspeed, and the peak potential with the increase of scanning speed to move forward. Tafelcurves of semi logarithm processing is a good linear curve fitting. the compositeelectrode in methylene blue solution for multi cycle voltammetry curves show thatcomposite electrode electric catalytic and stability are good. |
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