Produção do ânodo de ti/tio2-nanotubos/pbo2 para eletrogeração de oxidantes fortes e sua aplicação na eliminação eletroquímica do corante vermelho ácido 1

• Ano de defesa: 2016
• Autor(a) principal: Santos, José Eudes Lima
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Brasil; UFRN; PROGRAMA DE PÓS-GRADUAÇÃO EM QUÍMICA
• Palavras-chave em Português: PbO2 eletrodeposição; Nanotubos de TiO2; Radical Hidroxila; Persulfato; Oxidação anódica; Vermelho Ácido 1; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: https://repositorio.ufrn.br/jspui/handle/123456789/21971

This study aimed to synthesize the Ti/TiO2-nanotube/PbO2 electrode by anodizing electrochemistry and electroplating, investigate the production of strong oxidizing species and electrochemical degradation of synthetic textile dye Acid Red 1. Therefore, the TiO2 nanotubes were produced by anodizing electrochemistry in organic-inorganic mixed electrolyte, calcined and then decorated with PbO2 by electrodeposition. TiO2 nanotubes decorated with PbO2 were characterized by electron microscopy Scan, X-Ray Diffraction techniques and potentiodynamic measurements. The determination of strong oxidizing species was performed by ISCO method (persulfate) and spin trapping reaction by RNO (hydroxyl radical). The galvanostatic electrolysis of synthetic sample containing the dye AR1 in anodes Ti/Pt and Ti/TiO2-nanotube/PbO2 was monitored by UV-visible spectrometry and chemical oxygen demand. It was found that the Ti/TiO2-nanotube/PbO2 electrode has a high overpotential for the reaction of oxygen evolution is a bad electrocatalyst for this reaction. Furthermore, a significant production of hydroxyl radicals and persulfate is achieved in Ti/TiO2-nanotube/PbO2 compared to Ti/Pt mainly current density of 60 mA cm-2. It also showed better performance in the removal of AR1 complete discoloration with the same 90 min and decay of chemical oxygen demand by 64% the density of 60 mA cm-2 and greater efficiency in both current densities of 7.5 and 60 mA cm-2 across the electrode Ti/Pt. Therefore, the electrode Ti/TiO2-nanotube/PbO2 exhibits good catalytic properties for environmental applications, such as anodic oxidation. Furthermore, the concentration of the oxidizing electrode was dependent on the material and the anodic oxidation conditions.