EFEITO DOS PRECURSORES NA FORMAÇÃO DO GEL DE PENTÓXIDO DE VANÁDIO E CARACTERIZAÇÃO DE MATERIAIS MISTOS COM ARGILAS ESMECTITAS

Abstract

This dissertation focuses on the structural characterization of vanadium pentoxide gels formed by the same synthetic route, using different precursors in the synthesis. Were synthesized four gels V2O5.nH2O by percolation of aqueous solutions of salts of vanadium on columns containing ion exchange resin in acid form. It was found that with different vanadium salts and ion exchange resins, formed vanadium pentoxide gels with different structural and electrochemical. Was also explored the electrochemical behavior of gels on the surface of electrodes in organic solvent. Special attention has also been devoted in the development of mixed material formed by intercalation of gel vanadium in smectite clays. Interaction of these materials resulted in mixed materials stable in aqueous solution, formed by ion exchange of ions trapped between the interlayer spaces of clays by V2O5. In this context, studies of the structural and electrochemical behavior of mixed materials formed, indicated good interaction between the starting materials. The mixed materials emerge as attractive modifiers electrodes combining the good conductivity of the vanadium pentoxide gel with the property intercalation of clays. This context are presented mainly structural differences and the electrochemical behavior of the gels and mixed materials, using the techniques of scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS), simultaneous thermo analysis (TGA/DTA), x-ray diffractommetry (XRD), cyclic voltammetry (CV) and vibrational spectroscopy (Raman).