PbO_2-CeO_2电极的制备及其电化学性能

为解决传统铅银合金存在的铅污染和钛基PbO2(DSA)基体易钝化、使用寿命短等问题,以不锈钢为基体,用稀土Ce改性,制备了PbO2-CeO2电极。分析了PbO2的形成机理,通过析氧曲线、Tafel曲线、EDS能谱及扫描电镜考察了温度、电流密度、稀土Ce等对电极性能的影响及所制备电极的元素分布及表面形貌。结果表明:最佳制备工艺为190 g/L Pb(NO3)2,15 g/L Cu(NO3)2,0.5 g/L NaF,30 g/L CeO2,pH值为2～3,机械搅拌,温度70℃,电流密度10～20 mA/cm2,时间30 min;所制备的镀层平整、均匀,电化学性能优良,镀层中CeO2质量分数约为4%～6%;PbO2-CeO2电极析氧电位1 500 mV左右,节能性能明显优于传统惰性阳极。

Preparation and Electrochemical Properties of PbO2-CeO2 Electrodes

PbO2-CeO2 composite coating electrodes were prepared on stainless steel substrate by electroplating, and the formation mechanism of PbO2 was analyzed. The influences of temperature, current density and dosage of CeO2 on the electrochemical properties of PbO2-CeO2 composite coating electrodes were investigated by measuring the polarization curves and Tafel curves. The composition and morphology of as-prepared electrodes were analyzed using an energy dispersive spectrometer and a scanning electron microscope. It was found that the optimal electroplating bath consisted of 190 g/L Pb(NO3)2, 15 g/L Cu(NO3)2, 0.5 g/L NaF and 30 g/L CeO2. The optimal electroplating parameters were suggested as pH value of 2～3, temperature of 70 ℃, current density of 10～20 mA/cm2 and time of 30 min under mechanical stirring. Resultant PbO2-CeO2 composite coating was smooth and uniform, and contained 4%~6% CeO2. As-prepared electrode possessed an oxygen-evolution potential of 1 500 mV, showing much better energy-saving performance than traditional inert anode.