材料期刊网

采用化学共沉淀法,在二氧化钛(TiO2)颗粒表面包覆锑(Sb)掺杂二氧化锡(SnO2)制备了TiO2@ATO导电粉体.考察了不同粒径TiO2包覆ATO后对导电性能的影响,通过XRD、XPS、SEM和TEM对粉体进行了表征.将导电粉体制成复合电极,利用电化学工作站对其进行循环伏安(C-V)和交流阻抗分析,结果表明,C-V曲线的氧化还原峰随着扫描速率的增加分别向阳极和阴极移动,C-V曲线的形状没有发生明显的变化,说明导电粉体复合电极具有较高的倍率性能以及较小的内阻;交流阻抗表明,当粒径<25 nm时,高频区容抗弧半径最小,且曲线与横轴的交点值最小,同时低频区斜率较大,说明在一定范围内粒径越小,导电性能更好.上述结果表明,当TiO2粒径<25 nm时,TiO2@ATO粉体的电阻最小,导电性最好,此结果与用电阻率测定仪测得电阻率的结果一致.

The chemical coprecipitation method was adopted to prepare TiO2@ATO conductive powder by coating Sb-doped SnO2 on TiO2.The effect of the different particle sizes on the conductive properties of powder was examined, and the powder was confirmed by X-ray diffraction, X-ray photoelectron spectroscopy, Scanning electron microscope and transmission electron microscope.The results of cyclic voltammetry (C-V) curves and impedance measurements analyzing on the composite electrode investigated by the electrochemical workstation showed that with an increase in the scan rate, the anodic and cathodic peaks of the C-V curves shifted to higher and lower potentials, respectively, and the shape of the peaks didn't change obviously, instructing the composite electrodes was with high ratio of performance and low internal resistance.The impedance measurements instructed when the particle size was less than 25 nm, the capacitive reactance arc radius of high frequency region was the minimum, the intersection point value of the curve and the horizontal axis was the minimum and at the low frequency zone, slope was bigger, revealing within a certain scope, the smaller the particle size, the better the conductivity.The results showed that when the particle size was less than 25 nm, the resistance of TiO2@ATO powder was the minimum, the electrical conductivity was the best.This result was in accordance with the resistivity measured by electrical resistivity device.