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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Formation of Ti(III) and Ti(IV) states in Ti3O5 nano- and microfibers obtained from hydrothermal annealing of C-doped TiO2 on Si

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Author(s):
Stem, Nair [1] ; de Souza, Michele L. [2] ; Araujo de Faria, Dalva Lucia [2] ; dos Santos Filho, Sebastiao G. [1]
Total Authors: 4
Affiliation:
[1] Univ Sao Paulo, Escola Politecn, Lab Sistemas Integraveis, BR-05508900 Sao Paulo - Brazil
[2] Univ Sao Paulo, Inst Quim, LEM, BR-05508900 Sao Paulo - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Thin Solid Films; v. 558, p. 67-74, MAY 2 2014.
Web of Science Citations: 9
Abstract

In this work, it is investigated the formation of Ti(III) and Ti(IV) states at the surface and in the bulk of the Ti3O5 material grown as meshes of nano-and micro-fibers obtained from hydrothermal annealing of C-doped TiO2 on Si. The topography and distribution of the fibers in the meshes were characterized by atomic force microscopy. When the fiber distribution was more compact, a higher photoluminescence signal at 850 nm (1.46 eV) was obtained, indicating the presence of a higher number of defects corresponding to the Ti(III) sites. From X-ray photoelectron spectroscopy, it was obtained a Ti(III)/Ti(IV) ratio much lower than the expected value for the Ti3O5 phase (2 Ti(III): 1 Ti(IV)). The discrepancy was mainly attributed to the reaction of surface Ti(III) states of the Ti3O5 fibers with water during the hydrothermal annealing, resulting in surface Ti(IV) with - OH radicals. On the other hand, X-ray photoelectron spectroscopy also indicated that substitutional and interstitial carbon atoms coexist, elemental carbon exists in the samples due to the co-deposition process and, as a result, the carbon inside of the TiO2 rutile lattice is acting as one of the precursors for the formation of Ti3O5. (C) 2014 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 08/03636-5 - Applications of metallic nanocomposites in enhanced photochemical processes: plasmon effects in photocatalysis and photoelectrochemistry
Grantee:Michele Lemos de Souza
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
FAPESP's process: 06/58748-7 - Reactivity, dynamics and spectroscopy of complex systems
Grantee:Marcia Laudelina Arruda Temperini
Support Opportunities: Research Projects - Thematic Grants