【作者】 孙杰；

【导师】 刘晓霞；

【作者基本信息】 东北大学 ， 物理化学， 2010， 硕士

【摘要】 聚吡咯(PPy)环境稳定性高、具有良好的导电性和电化学活性,是导电高分子聚合物家族的重要成员。氧化铁与PPy复合可望进一步提高性能。在-0.7V-0.9V的电位范围内,以50V·s-1的扫描速率,通过循环伏安扫描进行吡咯(Py)的电化学聚合,研究了溶液pH值对聚吡咯(PPy)电化学活性的影响。在含柠檬酸的硫酸亚铁溶液中,-0.7V-0.9V的电位范围内,以50V.s-1的扫描速率,通过循环伏安扫描进行氧化铁(FeOx)的电化学沉积,研究了溶液pH值对FeOx电化学活性的影响。利用吡咯电化学聚合与氧化铁电化学沉积组合,研究了聚吡咯与氧化铁的电化学复合,制备了聚吡咯／氧化铁复合膜(PPy/FeOx)。复合膜的能谱图上出现元素铁的信号,通过XRD分析发现氧化铁在复合膜上主要以Fe203和Fe304的形式存在。复合膜的FT-IR谱图上出现PPy的特征振动吸收及与氧化铁有关的吸收峰。利用SEM观测了复合膜形貌,发现与氧化铁复合有利于聚合物颗粒细化。利用循环伏安法研究了复合膜电化学活性,利用循环伏安和恒电流充放电实验研究了复合膜超电容性能。研究了体系pH值、吡咯浓度等对电化学复合的影响,发现pH=8,硫酸亚铁的浓度为0.1mol·L-1,柠檬酸的浓度为0.1mol·L-1,吡咯浓度为0.1mol·L-1,氯化钾的浓度为0.2mol·L-1时,在-0.7V-0.9V电位范围内,以50mV.s-1的扫描速率循环伏安扫描50次后,可制备性能优良的PPy/FeOx复合膜。在1.0mol·L-1KCl (pH=1)溶液中对该复合膜进行恒电流充放电实验,结果表明,在0.5mA·cm-2的电流密度下,PPy/FeOx的比电容为301.3F g-1,而类似条件下制备的PPy的比电容为204.7F g-1,复合后比电容提高47%以上。更多还原

【Abstract】 Electropolymerization of pyrrole (Py) was conducted in a solution of pH=8containing0.1mol·L-1pyrrole and0.2mol·L-1KC1through cyclic voltammetries in the potential range of-0.7and0.9V at a scan rate of0.05V·s-1to afford film of polypyrrole (PPy). The influences of the pH of the electropolymerization media on electrocativities of the obtained PPy films were discussed. Electrodeposition of iron oxide was conducted in a solution of pH=8containing0.1mol·L-1ferrous sulphateand and0.1mol·L-1citric acid through cyclic voltammetries in the potential range of-0.7and0.9V at a scan rate of0.05V·S-1to afford FeOx film. The influences of the pH of the electropolymerization media on electrocativities of the obtained FeOx films were also discussed.Composite film of polypyrrole and iron oxide, PPy/FeOx, was obtained through the combination of electropolymerization of pyrrole and electrodeposition of iron oxide in solutions containing pyrrole, ferrous sulphateand, citric acid and KC1through cyclic voltammetries in the potential range of-0.7and0.9V at a scan rate of0.05V·s-1. Iron element was detected by Energy dispersive X-ray diffraction. Based on XRD, iron oxide existed in the composite film as Fe2O3and Fe3O4. Characteristic vibrations of both iron oxide and polypyrrole appered on the FT-IR spectrum of the composite film. Smaller particles were observed on SEM images of the composite film, compared to those of PPy. Electroactvities of the compoisted film were discussed by cyclic voltammetry. Supercapacitive properties of the composite film were discussed by both cyclic voltammetry and constant charging-discharging.The influences of the pH and pyrrole concentration on electro-co-deposition of polyprrole and FeOx films were investigated. Composite film with better properties was obtained through50times cyclic voltammetries in the potential range of-0.7and0.9V at a scan rate of0.05V·s-1, in the solution containing0.1mol·L-1ferrous sulphateand and0.1 mol·L-1citric acid,0.1mol·L-1pyrrole and0.2mol·L-1KCl at pH8. The composite film displayed a specific capacitance of301.3F·g-1, measured upon constant current charging-discharging at0.5mA·cm-2in1mol·L-1KCl (pH=1.0). The specific capacitance of PPy was204.7F·g-1, measured under the same condition. The specific capacitance of the composite film increased more than47%from that of PPy.更多还原