Electrochemical Synthese Of PPy/FeO_x And Its Pseudocapacitive Properties

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.