Structural and electrochemical studies of WO3 coated TiO2 nanorod hybrid thin films for electrochromic applications

This work presents the fabrication of Titanium dioxide (TiO2) nanorods/Tungsten oxide (WO3) hybrid thin films and the influence of nanostructures on the electrochromic behavior of the films. WO3 thin films were deposited at a constant substrate temperature of 673 K under various partial pressures of oxygen (ppO2). Also, Tungsten nanorods were grown on Fluorine doped tin oxide (FTO) coated glass substrate by hydrothermal process. Optimized WO3 films were coated on the TiO2 nanorod film by a sputter deposition method. Material, optical, electrical, and electrochemical analysis have been performed on the films using XRD, Raman, XPS, UV-Visible spectrometer and Cyclic voltammetry. The enhanced coloration efficiency (η) of the optimized WO3 films is found to be attributed to its large active surface area which favored H+ ions intercalation in the films. Also, the TiO2 nanorods/WO3 hybrid films exhibited a good electrochemical property in terms of the diffusion coefficient of 1.8 × 10−7 cm2/s better than those of pure WO3 and TiO2 nanorods.