Obtenção de nanotubos de TiO2 por anodização para eletrooxidação de corante azo alaranjado de metila em reator de fluxo

Abstract

The Azo dyes represent 60% of the dyes consumed by the industry. Brazil appears in fifth position of the largest textile producers in the world. The search for effluent treatment methods to mineralize wastewater treatment indicate the Advanced Oxidative Processes (AOP) has been intensely studied to optimizing the process to mineralize the dyes present in the wastewater. The objective of this work is the production and characterization of Ti electrodes surface-modified with Titanium Dioxide Nanotube (Ti/NTTiO2) to application in a flow reactor for the electro-oxidation of Methyl Orange (MO) azo dye. Potentiostatic anodization were carried out in NH4F/Glycerol solutions, using different parameters, the potential, the [NH4F] concentration and the anodization times, the TiO2 nanostructures were calcinated at 450 ºC for 30 minutes. For each electrode, the morphological and structural characterization obtained by Scanning Electron Microscopy (SEM), Raman Scattering Spectroscopy and X-Ray Diffraction (XRD). Electrochemical characterizations were carried out using the Cyclic Voltammetry (CV) technique to obtain the active surface area and reversibility values of the electrodes. After the characterizations, they were used in Ti/NTTiO2 as anodes in the electro-oxidation of MO in an electrochemical cell system and in a mezzo flow reactor for electro-oxidation of the dye. For the cell system in j = 8mA cm-² obtain a value of 98.98% color removal was added in 3 h of electro-oxidation, in mezzo reactor the values of 33% color removal were obtained, to the equal current density.