钛基Sn或Pb 氧化物涂层电极的制备与表征

采用热分解和电沉积方法分别制备了Ti/SnO2-Sb2O3,Ti/PbO2 和Ti/SnO2-Sb2O3/PbO2 三种电极.电镜照片表明,与热分解制备的Ti/SnO2-Sb2O3 电极表面呈"泥裂状"不同,电沉积Ti/PbO2 电极表面呈典型金刚石型结构;Ti/SnO2-Sb2O3/PbO2 电极的氧化物中间层使PbO2 结晶显著减小,而且增加了镀层PbO2 与钛基的结合力,在连续使用较长时间后电极表面出现"蜂窝状"腐蚀坑.EDAX和XRD 分析表明,虽然电极用于电化学氧化对氯苯酚后表层物相没有发生改变,但其组成元素的含量有所变化.与Ti/SnO2-Sb2O3 和Ti/PbO2 电极相比,Ti/SnO2-Sb2O3/PbO2 电极具有更高的电化学氧化性能.

PREPARATION AND CHARACTERIZATION OF Ti-BASED Sn AND Pb OXIDES ELECTRODES

The electrodes of Ti/SnO_2-Sb_2O_3,Ti/PbO_2 and Ti/SnO_2-Sb_2O_3/PbO_2 are prepared,respectively,by thermal decomposition and electrodeposition,which are characterized by spectral methods.SEM images show that,unlike to the "mud crack" surface of Ti/SnO_2-Sb_2O_3 electrode made by thermal decomposition,the surface of Ti/PbO_2 electrode made by electrodeposition appears diamond cubic structure.Moreover,the crystal size of PbO_2 decreases markedly when an intermediate layer of Sn-Sb oxides exists between the layers of Ti substrate and PbO_2.The honeycombed corrosion pits appear in the surface of Ti/SnO_2-Sb_2O_3/PbO_2 electrode after electrolyzing 4-chlorophenol for a long period.EDAX and XRD analyses indicate that although the phase transformation of electrode surface does not occur,the contents of the main elements in the electrode surface change with the increase of electrolysis time.Experimental results show that the electrochemical activity of Ti/SnO_2-Sb_2O_3/PbO_2 electrode is higher than that of the electrodes of Ti/SnO_2-Sb_2O_3 and Ti/PbO_2.