Mañana, JUEVES, 24 DE ABRIL, el sistema se apagará debido a tareas habituales de mantenimiento a partir de las 9 de la mañana. Lamentamos las molestias.
TiO2-reduced graphene oxide nanocomposites: Microsecond charge carrier kinetics
Entity
UAM. Departamento de Ingeniería QuímicaPublisher
Elsevier B.VDate
2020-01-01Citation
10.1016/j.jphotochem.2019.112112
Journal of Photochemistry and Photobiology A: Chemistry 386 (2020): 112112
ISSN
1873-2666 (online); 1010-6030 (print)DOI
10.1016/j.jphotochem.2019.112112Funded by
This work has been supported by the Spanish Plan Nacional de I+D+i through the project CTM2015-64895-R. Alvaro Tolosana-Moranchel thanks to Ministerio de Educación, Cultura y Deporte for his FPU grant (FPU14/01605) and (EST16/00065). The authors are also grateful to Technical Research Support Unit of Instituto de Catálisis y Petroleoquímica (CSIC)Project
Gobierno de España. CTM2015-64895-REditor's Version
https://doi.org/10.1016/j.jphotochem.2019.112112Subjects
Charge carrier dynamics; Fractal kinetic model; Reduced graphene oxide; TiO -rGO 2; Transient absorption spectroscopy; QuímicaNote
This Accepted Manuscript will be available for reuse under a CC BY-NC-ND licence after 24 months of embargo periodRights
© 2019 Elsevier B.V.Esta obra está bajo una licencia de Creative Commons Reconocimiento-NoComercial-SinObraDerivada 4.0 Internacional.
Abstract
In this work, transient absorption spectroscopy studies in the microsecond time scale were carried out to investigate the dynamics of photogenerated electron-hole pairs in TiO2-rGO nanocomposites, prepared by a hydrothermal method, under different atmospheres: N2, O2, and N2 saturated in CH3OH. Under N2 atmosphere, the transient absorption signal detected in the region between 450 and 700 nm dropped as the rGO mass concentration in the composite was raised. The electron transfer from TiO2 to rGO was confirmed by using a model based on fractal surfaces which describes the decay kinetics. In the presence of methanol as hole acceptor, P25-rGO 0.5% and 1% were able to reach the maximum transient absorption faster than the other studied nanocomposites. However, after 10 μs, the P25-rGO 0.1% nanocomposite yielded the highest transient absorption signal and the best conversion and initial reaction rate in the photocatalytic degradation of dichloroacetic acid in aqueous suspensions. The effect of rGO on free electrons was investigated by detecting the transient signal at 980 nm under N2 saturated in CH3OH, for the different samples. It was found that the measured signals followed the same response than at 660 nm further evincing the electron transfer process. No sensitization effect of rGO was observed when the samples were excited at 450 nm.
Files in this item
Google Scholar:Tolosana-Moranchel, A.
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Faraldos, M.
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Bahamonde, A.
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Pascual, L.
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Sieland, F.
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Schneider, J.
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Dillert, R.
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Bahnemann, D. W.
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