La/Ce掺杂钛基二氧化铅电极的制备及电催化性能研究

采用电沉积法制备了稀土La、Ce改性的钛基二氧化铅(Ti/PbO2)电极.利用SEM和XRD分析了电极的表面形貌和晶体结构,结果表明,稀土La、Ce掺杂后改变了电极表面的微观结构和晶面取向,使电极表面变得更加致密、均匀;用LS和CV测试了电极的电化学性能,分析表明,稀土La、Ce的掺杂提高了电极的析氧过电位和峰电流密度,改善了电极的催化性能.用所制备的不同掺杂量下的改性电极降解亚甲基蓝模拟染料废水(methylene blue,MB),结果表明,当La、Ce掺杂量分别为8.0g.L-1和5.0 g.L-1时,电极对MB及其COD的去除率达到最佳,分别为83.85%、79.95%和79.18%、76.21%,显示了良好的去除效果和催化性能,并在此基础上进一步分析了MB可能的降解路径和机制.

Preparation and Electro-catalytic Characterization on La/Ce Doped Ti-base Lead Dioxide Electrodes

Ti-base lead dioxide electrodes (Ti/PbO₂) doped with rare earth La, Ce were prepared by the electrode position. The surface morphology and crystal structure of the electrodes was analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), the results showed that, microstructure and crystal orientation of electrode surface changed after doping rare earth La, Ce, which made the electrode surface more dense and uniform. The electrochemical properties of the electrodes were tested by linear sweeping (LS) and cyclic voltammogram (CV), the experimental results show that, La, Ce doping improved the electrode overpotential of oxygen evolution and the peak current density, promoted the catalytic performance of the electrode. Different doping amount of modified electrodes were used to degrade methylene blue simulative dyeing wastewater, the results showed that, electrodes doped La and Ce respectively 8.0 g·L^-1 and 5.0 g·L^-1 have the best degradation efficiency and catalytic activity, for example, the removal of MB and its COD respectively researches 83.85%, 79.95% and 79.18%, 76.21%. The possible degradation pathways and mechanisms were also discussed.