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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.)

Photochemical reactivity of apical oxygen in KSr2Nb5O15 materials for environmental remediation under UV irradiation

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Author(s):
Matos, Juan ; Lanfredi, Silvania ; Montana, Ricmary ; Nobre, Marcos A. L. ; Fernandez, Maria C. ; Ania, Conchi O.
Total Authors: 6
Document type: Journal article
Source: Journal of Colloid and Interface Science; v. 496, p. 211-221, JUN 15 2017.
Web of Science Citations: 4
Abstract

The photocatalytic activity of a series of novel KSr2Nb5O15 materials was studied using the photooxidation of methylene blue as model reaction. The influence of the calcination time upon the crystalline structure and photoactivity was verified. Characterization was performed by XRD, SEM, FTIR, UV-Vis/DR, Helium picnometry, and N-2 and CO2 adsorption-desorption isotherms. The diffraction line profile and the refinement of the structural parameters of KSr2Nb5O15 were obtained from the XRD patterns by the Rietveld method. Data showed that samples were photoactive under UV irradiation, regardless the synthesis conditions. However, the calcination time had a clear influence upon the photocatalytic activity of the samples, being more efficient towards the degradation of the dye those obtained at a lower calcination time. Indeed, the sample calcined for 4 h showed up to 4 times higher photocatalytic activity than commercial TiO2. Additionally, a correlation between the photocatalytic activity and the displacement of the Nb ion from the central position in the {[}NbO6] octahedron was found. It is suggested that this fact causes an important polarization of the niobate structure. The apical oxygen in these samples is very reactive and can lead to the formation of superoxoradical anions (O-2(center dot-)) showing that KSr2Nb5O15 can be potentially used in photocatalytic reactions under UV irradiation. (C)2017 Elsevier Inc. All rights reserved. (AU)

FAPESP's process: 14/11189-0 - Catalytic performance as a function of nanostructuring of new oxides catalysts from the spray pyrolysis method
Grantee:Silvania Lanfredi
Support Opportunities: Regular Research Grants
FAPESP's process: 07/03510-9 - Structural characterization of nanopowders of semiconductor ferroelectric oxides
Grantee:Silvania Lanfredi
Support Opportunities: Regular Research Grants