PREPARAÇÃO DE COMPÓSITOS TERNÁRIOS FORMADOS POR ÓXIDO DE METAL DE TRANSIÇÃO/POLÍMERO CONDUTOR/CARBONO AMORFO PARA APLICAÇÃO EM SUPERCAPACITORES

Abstract

This work refers to the development of a simple and innovative method for the synthesis of ternary composites of different proportions based on amorphous carbon, polyaniline and manganese (IV) oxide for their future use in electrochemical supercapacitors. The process presented here consists, essentially, of 3 parts: (i) at first, it has been performed the oxidative treatment of amorphous carbon and the separated synthesis of pure MnO2 and polyaniline, when all the materials involved were structurally characterized by XRD, FTIR, RAMAN, DLS and SEM, and electrochemically characterized by cyclic voltammetry measurements, in order to identify its structural, morphological and electrochemical properties and then compared with those presented by the future ternary composites; (ii) synthesis of a binary C/MnO2 composite by the anchoring of the MnO2 particles on the oxidized sites of the amorphous carbon, which represents the first stage on the formation of the ternary composites. Its purpose was to identify possible structural and electrochemical changes caused by MnO2 surface layer in the comparison of the binary composite with its individual components. Therefore, this composite was characterized by the same methods mentioned above; (iii) synthesis and characterization of ternary composites on different proportions, based on the initial formation of binary C/MnO2 followed by in situ polymerization of aniline monomers on their surface structure. The purpose of the synthesis in different proportions is to obtain a response profile when small changes in the quantity of the constituent materials are introduced in the ternary composites. The characterization of the ternary composites were carried out by XRD, FTIR, RAMAN, DLS and SEM, which allow to identify possible structural and morphological changes showed by composites compared to the individual components and, by cyclic voltammetry measurements, when it was possible to notice the electrochemical behavior of these composites and define their specific capacitance values in parallel to their processes of charge storage and ions diffusion.