Preparation Of High-performance PbO₂ And Its Electro-oxidation Performance

Pre-treatment of the azo dyeing acid wastewater by pulse electrolysis was investigated. The high-performance lead dioxide anodes were prepared. These researches would be valuable for lead dioxide preparation and its application.The pre-treatment of the azo dyeing acid wastewater pre-treatment by pulse electrolysis was studied, The results indicated that the COD removal rate was 58.97% , and that the color removal rate reached 91.4%, and that the BOD5/CODCr of sampled water increased from 0.09 to 0.34 under the optimum conditions: electrolysis time, 40min; peak voltage, 12 V; pulse frequency, 600 Hz; duty factor, 50%. It was found that the current efficiency of pulse electrolysis almost was two fold of that of direct current electrolysis. A comparison between the common micro-electrolysis of Fe/C bed and the pulse electrolysis in cost indicated that the pulse electrolysis also had advantages, showing an excellent applicating prospect.The polytetrafluoroethylene (PTFE)-doped PbO₂ electrode on Ti substrate was prepared from the sulfamic acid bath or nitric acid bath. SEM revealed that Ti/PTFE-PbO₂ from sulfamic acid bath had more regular morphology with lower size crystals of ³2nm than Ti/PTFE-F-PbO₂ of ⁸7nm from nitric acid based on Scherrer equation. The service life of Ti/PTFE-PbO₂ from sulfamic acid bath was predicted to more than 7 yrs (a current density of 0.1 A·cm-2). During the process of treating 4-chlorophenol-contaminated water, Ti/PTFE-PbO₂ from sulfamic acid bath not only had good electro-catalytic activity,which increased the 4-chlorophenol removal by 11.7%, but also exhibited high electrochemical stability, showing an excellent application potential.CeO₂-PTFE co-dopedβ-PbO₂ was obtained from bath containing lead acetate trihydrate and sulfamic acid. Results from XRD and SEM techniques indicated that the main crystal grainβ-PbO₂ was very uniform and compact and the crystalline size was 9¹3 nm. The Ti/CeO₂-PTFE-PbO₂ from lead acetate trihydrate / sulfamic acid bath could get a higher over-potential and the accelerated electrolysis life could reach 1151h. The Energy Dispersive X-ray analysis verified the strong stability of the deposits. It also got higher 4-chlorophenol removal by 5% than Ti/CeO₂-PTFE-PbO₂ from lead nitrate / nitric acid bath which indicated its high catalytic activity.