Preparation And Application Of The Metal-oxide-coated Electrodes On Ti Base

This paper focused on Ti/Sn-Sb doped electrodes, doping elements included Fe, Mn, Ni, Ru and Co to prepare electrodes by thermal brushing decomposition. The electrocatalytic performance of doped electrodes was also studied.Based on Ti/Sn-Sb electrode, the coating solution was prepared according to the atomic mass ratio of Sn, Sb and X(X on behalf of doping elements) was 100:10:5. Then the electrodes were calcined at 475℃. The results showed that thermal brushing decomposition could easily lead to a "cracking" phenomenon on the surface of the active coating, affecting the electrode catalytic activity and lifetime. Compared with other doped electrodes, Ti/Sn-Sb-Mn had the longest lifetime.Then the nitrobenzene wastewater was dealt with by Ti/Sn-Sb-Mn modified electrode, which using stainless steel as the cathode plate, and the area of the plate was 25cm2. The results showed that when electrolytic concentration of anhydrous Na2SO4 was 15g/L, the initial pH was 6, the current density was 20mA/cm2, and the electrode interval was 2cm, the concentration of nitrobenzene was degraded from 98.3mg/L to 4.1mg/L, the removal rate reached 95.9%, and the concentration of TOC was degraded from 48.5mg/L to 12.3mg/L, the removal rate reached 71%. It showed that the Ti/Sn-Sb-Mn electrode had the ability to degrade nitrobenzene.The changes of water temperature and color, as well as the dropping of electrodes were studied in the electrochemical oxidation process of nitrobenzene wastewater. The results showed that the change ratio of water temperature was greater with the higher current density, and the final temperature was relatively high either. But pH, electrode interval and the initial concentration of wastewater had no effect on temperature rising. The color of the solution was slightly changed because of metal ions getting into the solution during the process of consumption of the electrode active coating. In the conditions that the solution was acidic and the current density was relatively large, the electrochemical reaction was more violent. Because of this reason, the active coating was consuming seriously, resulting in quicker dropping time and larger losing area of the electrode.