Nature and photoreactivity of of TiO2-rGO nanocomposites in aqueous suspensions under UV-A irradiation
Entity
UAM. Departamento de Ingeniería QuímicaPublisher
Elsevier B.VDate
2019-02-01Citation
10.1016/j.apcatb.2018.09.070
Applied Catalysis B: Environmental 241(2019): 375-384
ISSN
1873-3883 (online); 0926-3373 (print)DOI
10.1016/j.apcatb.2018.09.070Funded by
This work has been supported by the Spanish Plan Nacional de I+D+i through the project CTM2015-64895-R and CTM2016-76454-R. Alvaro Tolosana-Moranchel thanks to Ministerio de Educación, Cultura y Deporte for his FPU grant (FPU14/01605)Project
Gobierno de España. CTM2015-64895-R; Gobierno de España. CTM2016-76454-REditor's Version
https://doi.org/10.1016/j.apcatb.2018.09.070Subjects
ATR-FTIR; Mechanism; Oxalic acid; Reduced graphene oxide; TiO -rGO 2; QuímicaNote
This Accepted Manuscript will be available for reuse under a CC BY-NC-ND licence after 24 months of embargo periodRights
© 2018 Elsevier B.V.Esta obra está bajo una licencia de Creative Commons Reconocimiento-NoComercial-SinObraDerivada 4.0 Internacional.
Abstract
Different studies to unravel the nature of the activity of TiO2 photocatalysts modified with rGO were carried out. The band edge potentials and the band gap energy of the nanocomposites were determined by performing electrochemical impedance and UV–vis diffuse reflectance measurements, respectively. However, no changes were observed when TiO2 is modified with rGO. Nevertheless, the presence of rGO in the hybrid composite led to a low charge transfer resistance across the electrode-electrolyte interface, observing even a tenfold increase in the photocurrent values in methanol photo-oxidation for P25-rGO 1%. Moreover, a higher oxygen reduction current was found when increasing the rGO concentration that could lead to a higher ROS formation. In order to analyze the beneficial properties of the hybrid materials, the influence of rGO doping ratio on oxalic acid photocatalytic degradation and on oxalic acid adsorption onto the nanocomposites surface was studied, both of them under UV-A light irradiation. In addition, the photoactivity of the conduction band electrons and the valence band holes was investigated by performing EPR and transient absorption spectroscopy measurements under UV-A illumination in O2 or N2 atmospheres. It was demonstrated that rGO behaved as an electron acceptor. Finally, TAS results under O2 and N2 atmospheres proved that the role played by rGO was not as crucial in excess of dissolved O2 as in N2 atmosphere. These findings agree with the observed photocatalytic activity and EPR measurements. Nevertheless, generation of HO[rad] in N2 saturated suspensions was highly increased with the addition of rGO
Files in this item
Google Scholar:Tolosana-Moranchel, A.
-
Casas de Pedro, José Antonio
-
Bahamonde, A.
-
Pascual, L.
-
Granone, L. I.
-
Schneider, J.
-
Dillert, R.
-
Bahnemann, D. W.
This item appears in the following Collection(s)
Related items
Showing items related by title, author, creator and subject.
-
TiO2-reduced graphene oxide nanocomposites: Microsecond charge carrier kinetics
Tolosana-Moranchel, A.; Faraldos, M.; Bahamonde, A.; Pascual, L.; Sieland, F.; Schneider, J.; Dillert, R.; Bahnemann, D. W.
2020-01-01