Nanostructured Iron Oxide Films Prepared by Electrochemical Method for Electrochemical Capacitors

Nanostructured iron oxides were electrodeposited anodically onto nickel substrate in aqueous solution at room temperature. Deposited films after annealing at 300 degrees C are characterized as rhombohedral Fe2O3. The morphology of the porous film deposited at high current density shows nanosheets of 10-16 nm in thickness. A film deposited at low current density has aggregates of nanorods. Electrochemical impedance results show that the film of randomly distributed nanosheets has a higher percentage of large pores than the film of aggregated nanorods. Consequently, specific capacitance of the film with nanosheets is higher than that of the film with aggregated nanorods at galvanostatic charge/discharge.