Preparation And Research Of K₃[Fe(CN)₆] And Graphite Co-doped Modified Ti/PbO₂ Electrode

Pb-Ag anodes currently commonly used in hydro-zinc smelting have the problems of excessively high oxygen evolution potential(about 1.8-2V at a current density of0.05A/cm²)and poor mechanical properties.Because of its own advantages,Ti/PbO₂electrodes have been successfully used as anode materials in hydrometallurgical extraction processes such as Cu and Ni.Due to the characteristics of zinc electrowinning production is that the electrolyte has many impurities and high acidity,the PbO₂ coating is easy to fall off when the Ti/PbO₂ electrode is applied.In order to further improve the performance of Ti/PbO₂electrode,this article is based on K₃[Fe(CN)₆]and GP co-doping modification to prepare Ti/PbO₂ electrode,optimize the electrodeposition conditions of?-PbO₂ active layer,and improve the adhesion strength of PbO₂ composite coating As well as electrochemical performance,it provides certain theoretical support for its promotion and use in the hydro-zinc smelting industry.(1)The optimal electrodeposition conditions of?-PbO₂ active layer were determined as follows:current density 15 m A/cm²,temperature 65?,time 2h.(2)The modification of the electrode by doping K₃[Fe(CN)₆]and GP in the electrodeposition solution was successful,and the?-PbO₂ grain size was reduced to33.64nm At the same time,it effectively improves the surface morphology of the electrode,enhances the bonding force between the plating layer and the substrate,and prolongs the service life of the electrode.(3)The Ti/PbO₂-K₃[Fe(CN)₆]-GP electrode prepared by co-doping K₃[Fe(CN)₆]with a concentration of 10mmol/L and 8g/L GP has better electrocatalytic performance And it has strong reversibility,the oxygen evolution potential is 191m V lower than the traditional Ti/PbO₂electrode,the current efficiency is increased by 2.78%,the electrode coating is more dense and uniform,the electrode coating bonding force is enhanced,so the life span is extended to 267h.(4)The failure of Ti/PbO₂-K₃[Fe(CN)₆]]-GP electrode form is:the surface coating gradually becomes thinner due to slow corrosion,the substrate is exposed after the coating disappears,and the main reason for passivation and failure;the main reason for the failure of the traditional Ti/PbO₂ electrode is:once the coating falls off,the substrate is exposed immediately,and then the passivation leads to the electrode Invalidate.That is,Ti/PbO₂-K₃[Fe(CN)₆]-GP electrode has better availability and longer service life.