Electrochemical Properties and Band Gap Variation of Polyaniline Due to the Presence of ZnO

Abstract

Composite thin films of polyaniline (PAN)/ZnO are synthesized via electropolymerization (ECP) process in acidic medium on ITO (working electrode) with platinum mesh as a counter electrode and Ag/AgCl as a reference electrode. Acidic medium helps in polymerization and enhances the crystallinity of PAN. PAN films that are obtained in the presence of sulfuric acid give partial crystallinity in its high conducting form, i.e., emeraldine salt. Inorganic metal oxide–organic polymer thin film was used to get a new type of composite nanostructures. The cyclic voltammetry and chronoamperometric properties were investigated by potentiostat for different doping percentages of ZnO with a constant Molar concentration of PAN. Current conduction properties are found to be increased in the presence of ZnO particles. Optical properties were investigated using UV–Vis and photoluminescence spectroscopy. Photoluminescence shows emission in the blue, green and yellow regions. Band gap variation has also been calculated with the help of Tauc’s plot which found to be decreasing with the increase of doping percentage of ZnO.