La-PTFE共掺杂二氧化铅电极的制备及其性能研究

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

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0.15mol.L-1,电极极距为6.0cm的酸性条件下降解亚甲基蓝的效果最佳.降解3.0h后,对100mg.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.

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.