Photoinduced Paramagnetic Centers in Nanocomposites Formed by Titanium Dioxide and Myristic Acid

Autor(es)

Magon, Claudio Jose ^[1] ; Zarto, Harold Lozano ^[1] ; Donoso, Jose Pedro ^[1] ; Eckert, Hellmut ^[1] ; Devis, Sindy ^[2] ; Benavente, Eglantina ^{[3, 4]} ; Villarroel, Roberto ^[5] ; Gonzalez, Guillermo ^[6]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13566590 Sao Carlos, SP - Brazil

^[2] Univ SEK, Fac Ciencias Salud, Biomed Inst Invest Interdisciplinar Ciencias, Santiago - Chile

^[3] Univ Tecnol Metropolitana, Fac Ciencias Nat Matemat & Medio Ambiente & Progr, Dept Quim, Santiago 7750000 - Chile

^[4] Univ Tecnol Metropolitana, Programa Inst Fomento Invest Desarrollo & Innovac, Santiago 7750000 - Chile

^[5] Pontificia Univ Catolica Chile, Inst Fis, Santiago 7750000 - Chile

^[6] Univ Chile, Fac Ciencias, Dept Quim, Santiago - Chile

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry C; v. 125, n. 12, p. 6773-6786, APR 1 2021.
• Citações Web of Science: 0

Resumo

An electron paramagnetic resonance (EPR) study has been carried out on the hybrid layered nanocomposite formed by TiO2 and myristic acid. The samples were characterized by means of X-ray diffraction (XRD), thermogravimetric analysis, solid-state NMR, scanning electron microscopy (SEM), spectral absorbance (UV-vis), and Raman and infrared spectroscopy (FTIR). X-band continuous wave (CW)-EPR was used to investigate the photo-induced paramagnetic species generated in the nanocomposite by UV irradiation at 365 nm in vacuum and in ambient atmosphere and characterized spectroscopically at 90 K. Various paramagnetic species were identified and characterized by their Hamiltonian parameters. They include disordered isolated Ti3+ centers, dimeric units producing S = 1 triplet species, and superoxide radicals, (ROO center dot), whose concentrations were monitored as a function of temperature and annealing times during the course of well-defined temperature cycling protocols. (AU)

• Processo FAPESP: 19/02672-2 - Desenvolvimento de técnicas espectroscópicas e computacionais para caracterização de vidros e vitro-cerâmicas por RMN e RPE
• Beneficiário: Harold Ivan Lozano Zarto
• Modalidade de apoio: Bolsas no Brasil - Programa Capacitação - Treinamento Técnico
• Processo FAPESP: 13/07793-6 - CEPIV - Centro de Ensino, Pesquisa e Inovação em Vidros
• Beneficiário: Edgar Dutra Zanotto
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs