Photochemical insights of TiO2 decorated mesoporous SBA-15 materials and their influence on the photodegradation of organic contaminants

Autor(es)

Conceicao, D. S. ; Graca, C. A. L. ; Ferreira, D. P. ; Ferraria, A. M. ; Fonseca, I. M. ; Botelho do Rego, A. M. ; Teixeira, A. C. S. C. ; Vieira Ferreira, L. F.

• Tipo de documento: Artigo Científico
• Fonte: Microporous and Mesoporous Materials; v. 253, p. 203-214, NOV 15 2017.
• Citações Web of Science: 11

Resumo

Mesoporous silica, SBA-15, decorated with different amounts of TiO2 (anatase) were prepared by a sol-gel method followed by hydrothermal treatment and calcination, in the presence of a soft template, copolymer Pluronic 123. Tetraethyl orthosilicate (TEOS) was used as the SiO2 precursor and commercially available TiO2 anatase nanoparticles as the supported photocatalyst. The materials were characterized by transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDS), N-2 adsorption desorption isotherms, raman spectroscopy, ground state diffuse reflectance (GSDR), laser induced luminescence (LIL) and X-ray photoelectron spectroscopy (XPS). The zeta potentials of the pure SBA-15, TiO2/SBA-15 substrate and the commercial anatase sample were monitored through a complete range of pH values. All the nanomaterials developed in this work were studied in terms of their photoactivity in the UV range and in the visible range, separately. In the first case, hydroxyl radicals (center dot OH) were confirmed to be the key active oxidizers in the photodegradation of the pesticide amicarbazone in aqueous medium. On the other hand, in the visible range, and following a dye sensitization process via a fluorescent rhodamine-like dye, two different mechanisms could be identified for the formation of the superoxide radical anion,O-2(center dot-). (C) 2017 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 13/50218-2 - CEPEMA - Centro Cooperativo em Engenharia Ambiental
• Beneficiário: Claudio Augusto Oller do Nascimento
• Modalidade de apoio: Auxílio à Pesquisa - Temático