Obtenção e caracterização de materiais catalisadores da oxidação de contaminantes em solução aquosa

• Ano de defesa: 2010
• Autor(a) principal: Marcio Guimaraes Coelho
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: oxidação de contaminantes; Fotocatalise; corantes; Catalisadores; Nanotecnologia; Espectrometria de massa; Quimica inorganica
• Link de acesso: http://hdl.handle.net/1843/SFSA-86HQ46

"Sn" and "Al" materials, with different reasons in Sn/Al2O3 mass were obtained, characterized and tested as catalysts for the oxidation of indigo carmine dye. The characterization of the materials confirmed the presence of Sn (IV) in all samples. It was observed only one phase, the SnO2. The particle size obtained was 22 to 36 nm. Thephotocatalytic tests showed the photoactivity of this material. The IC dye was completely degraded generating products, which the degradation mechanism was proposed based on the results of ESI-MS. Materials of "Sn" and "Ti", with different reasons Sn/TiO2 mass, were also obtained, characterized and tested as catalysts for the oxidation of thedye indigo carmine and methylene blue (MB). It was observed the presence of Sn(IV) in all samples, the TS15 and TS30 samples treated in H2 atmosphere, there is also the presence of Sn(0). There was formation of TiO2 anatase phase. The values of band gap of the materials were obtained from the analysis of the UV / Vis results, the valuesobtained range from 3.16 to 3.22 eV. In the micrographies obtained, it is not possible to differentiate between oxides of tin and titanium in the samples, except for TS15 and TS30 samples obtained in H2 wave we observed the presence of white spheres due to the formation of Sn(0). The materials showed less surface area when treated in H2atmosphere, in the material treated in an atmosphere of O2, as the proportion of "Sn" in the samples is increased, there is an increase in surface area until the mass ratio, Sn / TiO2, is of 0.30. The materials were tested in the reaction of discoloration of IC and MB dyes. The mechanism of degradation of dyes was also proposed based on the results ofESI-MS. Finally, it was obtained, characterized and tested in the oxidation of IC dye, a material consisting of Fe3 + doped in powder of bovine bone. The Mössbauer spectra of Fe indicate the existence of Fe3+ and Fe2+ in the material. This is an amorphous composite. This showed a higher surface area after impregnated and heat-treated, and it was activein the reaction of the oxidation of the IC dye. The mechanism involved in the reaction of degradation was proposed based on the results obtained by ESI-MS and is according to what was proposed for the other materials mentioned above. Cytotoxic test were performed with the primary color IC solutions, before and after degradation. It wasobserved they have the same cytotoxicity.