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研究论文

Preparation and electro-catalytic characterization of rare earth La-PTFE co-doped lead dioxide electrodes

基金项目：浙江省自然科学基金(No.Y5090272);浙江省重点科技创新团队项目(No. 2011R09048-04); 高等学校博士学科点专项科研基金(No. 20113317120004)

摘要：以Ti为基体,掺杂La₂O₃和聚四氟乙烯(PTFE),通过电沉积法制备了Ti/SnO₂+Sb₂O₃/PTFE+La₂O₃+β-PbO₂电极,并将所制备的电极应用于亚甲基蓝模拟染料废水的降解.结果发现,与常规的Ti/SnO₂+Sb₂O₃/PTFE+β-PbO₂电极相比,Ti/SnO₂+Sb₂O₃/PTFE+La₂O₃+β-PbO₂电极对亚甲基蓝及COD有较好的去除效果.含有La₂O₃活性层的Ti/SnO₂+Sb₂O₃/PTFE+La₂O₃+β-PbO₂电极在电解质浓度为0.15 mol·L^-1,电极极距为6.0 cm的酸性条件下降解亚甲基蓝的效果最佳.降解3.0 h后,对100 mg·L^-1亚甲基蓝的去除率可达到97.92%,对COD去除率为93.39%.SEM结果显示,Ti/SnO₂+Sb₂O₃/PTFE+La₂O₃+β-PbO₂电极表面颗粒鲜明,比表面积增大,改善了电极的微观结构和催化效果.电化学测试表明,La₂O₃的掺杂显著提高了二氧化铅电极的析氧过电位,显示出较好的应用前景.

Abstract：Ti-based PbO₂ electrodes(Ti/SnO₂+Sb₂O₃/PTFE+La₂O₃+β-PbO₂)co-doped with La₂O₃ and PTFE were prepared by the electro-deposition. Compared with conventional Ti/SnO₂+Sb₂O₃/PTFE+β-PbO₂ electrodes, Ti/SnO₂+Sb₂O₃/PTFE+La₂O₃+β-PbO₂ electrodes have higher removal rate of methylene blue and its COD, in the process of degrading simulative dyeing wastewater of methylene blue. The results showed that the electrode doped with La₂O₃ (Ti/SnO₂+Sb₂O₃/PTFE+La₂O₃+β-PbO₂) had the best degradation efficiency under the acid condition with electrolyte concentration of 0.15 mol·L^-1 and electrode spacing of 6.0 cm. The removal rate of 100 mg·L^-1 methylene blue reached 97.92% and its COD value declined to 93.39% after degradation for 3.0 h. SEM showed that Ti/SnO₂+Sb₂O₃/PTFE+La₂O₃+β-PbO₂ electrode had clearer particles and larger surface that improved the micro-structure and catalytic effects of the electrode. The results of electrochemical test demonstrated that La₂O₃ doping can significantly increase oxygen over-potential of lead dioxide indicating good application prospects.