Facile electrochemical synthesis of rGO/PANI/ZnO heterostructure for energy storage applications

Abstract

The combination of carbon nanomaterials, conducting polymers, and metal oxides provides a superior combination of high-quality supercapacitor (SC) materials. The carbon based materials are best known for its high electric double layer capacitance (EDLC) and the polymers like polyaniline (PANI) for pseudocapacitance. Transition metal oxides (TMOs) exhibit a combination of pseudocapacitance and EDLC owing to their unique chemical and morphological behaviour. The presence of an electric double layer capacitance and pseudocapacitance in the hybrid by using these combinations helps to obtain a higher specific capacitance. In this study, reduced graphene oxide (rGO), polyaniline (PANI), zinc oxide (ZnO) were combined using the different electrodeposition methods on ITO substrate. RGO can electrophoretically deposited using GO and the simultaneous reduction occurs during deposition. The highly stable PANI in emeraldine salt oxidation state was obtained using anodic electrodeposition. ZnO nanopowders also can be electrophoretically deposited over rGO/PANI. This hybrid material is expected to exhibit superior electrochemical properties and be environmentally friendly. The morphologies and quality of the samples were analyzed using scanning electron microscopy, Raman spectroscopy and X-ray diffraction techniques and found to be morphologically suitable for energy storage devices like supercapacitors.