Preparation and Characterization of the Ti/IrO2/WO3 as Supercapacitor Electrode Materials

WO3 films have been prepared onto IrO2-coated Ti substrate by electro-deposition, and as-deposited and annealed films have been characterized by using Raman spectroscopy. It was found that the as-deposited film consists of orthorhombic WO3 center dot H2O phase, which transforms to amorphous WO3 by annealing at 250 degrees C and to monoclinic phase by annealing at and above 350 degrees C. All electrochemical experiments were carried on Ti/IrO2/WO3 annealed at 450 degrees C. The open-circuit potential could change significantly due to the hydration of the coating film. However this process is fairly slow. Reproducible voltammograms could be obtained quickly, further revealing high electrochemical stability of the Ti/IrO2/WO3 electrode. And the shapes of CV show the approximate rectangular mirror image, showing the typical characteristic of capacitive behavior. The specific capacitance obtained at a scan rate of 50 mV s(-1) is 46 F g(-1).