Study On Preparation And Application Of New Ti-Supported Lead Dioxide Electrode

With the development of the electrochemistry industy, conventional anodes showed more and more limitations. Lead dioxide is characterized by stable chemical property, anticorrosion, high electric conductivity, etc, So it is applied in various industries. In this paper, preparation of the excellent performance lead dioxide electrode and it's usage for direct determination COD and phenol degradation were studied. The results provided technical basis for choosing electrodes for electrochemistry industy production and had certain theoretic significance and applied value.In the basis of summarized current methods of Ti/PbO₂ electrode preparation, a new method that covered stannum and antimony mixed oxide compounds as bottom was provided in this paper;Thenα-PbO₂ was electrodeposited in alkaline medium as mesosphere; At last, electrodepositedβ-PbO₂ in acidity medium was used as surface layer.The crystal phase and the micrographs of the electrode surface layer were analyzed by SEM and XRD respectively.The results showed that the Ti/PbO₂ electrode surface layer,which was uniform,even and crack-free, crystal grain distribution was closely and regular, wasβ-PbO₂ mainly. The results of phenol degradat test showed that the electrode have high catalytic activity.Curve of linear sweep voltammetric showed that the electrode had high oxygen evolution potential, which realized high catalytic activity and wider potential window, and could adapt to various organic compounds degradation.Direct determination of COD by Ti/PbO₂ electrode was discussed. By experiment the optimum determination condition was as follows: working voltage was 1.4v, sodium sulfate electrolyte concentration was 0.02 mol/L, measuring the current value change after electrolysis 1.5min, the optimum COD determination range was 20-200mg/L.After determination, the Ti/PbO₂ electrode was regenerated. The optimum regeneration condition was as follows: regeneration solution concentration was 0.5mol/L, regeneration voltage was 1.8v and the regeneration time was 2.0min; The surface of electrode was regenerated by bubbling in order to get a good reproducibility. The results showed that the method keeps good consistency with standard method when used in actual water samples.The optimum condition of electrocatalytic oxidation degradation of phenol waste water using Ti/PbO₂ electrode was determined as follows:current density was 30mA/cm², sodium sulfate electrolyte concentration was 0.1mol/L, pH was 3.0, degradation time was 2.5h. Under this condition, the phenol remove rate was 91.3%.The ultraviolet spectrum of phenol degradation at different time showed that phenol degradation was a complex process, which experienced quinone intermediate products and then advanced degraded. The kinetics study showed that phenol degradation reaction accorded apparently with the-first-order kinetics.