(615a) Transparent Polyaniline Nanocomposite Films for Electrochromism and Electrochemical Energy Storage Applications

In the paper, transparent polyaniline (PANI) nanocomposite films for electrochromism and electrochemical energy storage applications were investigated. Tungsten oxide (WO₃) and graphite oxide (GO) were selected as the inorganic nanoparticles. The nanocomposite films were fabricated via direct electropolymerization of the aniline monomers on to the WO₃ or GO coated-indium tin oxide (ITO) glass slides prepared by spin coating technique. The chemical structure and morphology as well as the crystalline structure of the composite films were studied using Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), and X-ray diffraction (XRD). The results confirmed the chemical interactions between the PANI matrix and the nanoparticles. The optical properties and electrochemical capacitive behaviors of the composite films for electrochromic (EC) and energy storage devices applications were investigated using spectroelectrochemistry (SEC), cyclic voltammetry (CV) and galvanostatic charge-discharge measurements. Multi-color electrochromism at different potentials were observed in the nanocomposite films. The nanocomposite thin films also exhibited higher coloration efficiency and comparable areal capacitances as compared to those of the pure PANI. Significantly enhanced cycling stability was found in the nanocomposite thin films, which is believed to arise from the interactions between the polymer matrix and nanoparticles.