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Understanding the Origin of the Photocatalytic CO2 Reduction by Au- and Cu-Loaded TiO2: A Microsecond Transient Absorption Spectroscopy Study

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Understanding the Origin of the Photocatalytic CO2 Reduction by Au- and Cu-Loaded TiO2: A Microsecond Transient Absorption Spectroscopy Study

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dc.contributor.author Baldovi, Herme G. es_ES
dc.contributor.author Neatu, Stefan es_ES
dc.contributor.author Khan, Anish es_ES
dc.contributor.author Asiri, Abdullah M. es_ES
dc.contributor.author Kosa, Samia A. es_ES
dc.contributor.author García Gómez, Hermenegildo es_ES
dc.date.accessioned 2016-05-12T11:54:23Z
dc.date.issued 2015-03-26
dc.identifier.issn 1932-7447
dc.identifier.uri http://hdl.handle.net/10251/63977
dc.description.abstract Recent photocatalytic data for CO2 reduction by H2O using simulated sunlight have shown that, while TiO2 Evonik P25 containing Au nanoparticles (NPs; Au/P25) generates considerably higher amounts of hydrogen than methane, when P25 contains Au-Cu alloy NPs the selectivity toward methane increases dramatically. To gain insight into this photocatalytic behavior, in the present work we have performed a transient absorption spectroscopy study in the microsecond time scale of three samples, namely, Au/P25, Cu/P25, and (Au, Cu)/P25 using 355 (UV) and SR nm (visible) lasers. The transient spectra exhibit as common features a narrower peak at about 320 nm and a broad band from 400 to 800 run. Using oxygen as electron quencher and methanol as hole quencher, the transient signals have been assigned to charge separation. Several cases were observed, including: (i) absence of quenching attributed to the lack of accessibility of the quencher to the site, (ii) quenching of the signal, or (iii) increase of the transient signal intensity attributed to less charge recombination by removal of one of the charge carriers. Of relevance to understand the origin of the photo catalytic CO2 reduction by H2O is the quenching of the charge separated state by these two reagents. In this way, it was observed that H2O exerts a remarkable influence to the transient signal, quenching its intensity in the three samples at the two irradiation wavelengths, except for (Au, Cu)/P25 upon 532 run excitation. Importantly, the distinctive behavior due to the presence of Cu has been attributed to the observed quenching by CO2 of the broad 400-800 nm band when excitation is performed with UV 355 nm light. es_ES
dc.description.sponsorship Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa Grant CTQ2012-32315), the Deanship of Scientific Research (DSR), King Abdulaziz University, under Grant No. 75-130-35-HiCi, and Marie Curie Project PIEF-GA-2011-298740 is gratefully acknowledged. The authors acknowledge technical and financial support of KAU. We also thank the Generalidad Valenciana for postgraduate research contract to H.G.B. (Prometeo 2012/2013). en_EN
dc.language Inglés es_ES
dc.publisher American Chemical Society es_ES
dc.relation Spanish Ministry of Economy and Competitiveness CTQ2012-32315 es_ES
dc.relation Deanship of Scientific Research (DSR), King Abdulaziz University 75-130-35-HiCi es_ES
dc.relation Marie Curie Project PIEF-GA-2011-298740 es_ES
dc.relation KAU es_ES
dc.relation Generalidad Valenciana es_ES
dc.relation.ispartof Journal of Physical Chemistry C es_ES
dc.rights Reserva de todos los derechos es_ES
dc.subject heterogeneous catalysis es_ES
dc.subject metal organic frameworks es_ES
dc.subject aerobic oxidation es_ES
dc.subject MIL-101 as catalyst es_ES
dc.subject benzylic oxidation es_ES
dc.subject.classification QUIMICA ORGANICA es_ES
dc.title Understanding the Origin of the Photocatalytic CO2 Reduction by Au- and Cu-Loaded TiO2: A Microsecond Transient Absorption Spectroscopy Study es_ES
dc.type Artículo es_ES
dc.embargo.lift 10000-01-01
dc.embargo.terms forever es_ES
dc.identifier.doi 10.1021/jp5106136
dc.rights.accessRights Cerrado es_ES
dc.contributor.affiliation Universitat Politècnica de València. Departamento de Química - Departament de Química es_ES
dc.contributor.affiliation Universitat Politècnica de València. Instituto Universitario Mixto de Tecnología Química - Institut Universitari Mixt de Tecnologia Química es_ES
dc.description.bibliographicCitation Baldovi, HG.; Neatu, S.; Khan, A.; Asiri, AM.; Kosa, SA.; García Gómez, H. (2015). Understanding the Origin of the Photocatalytic CO2 Reduction by Au- and Cu-Loaded TiO2: A Microsecond Transient Absorption Spectroscopy Study. Journal of Physical Chemistry C. 119(12):6819-6827. doi:10.1021/jp5106136 es_ES
dc.description.accrualMethod Senia es_ES
dc.relation.publisherversion http://dx.doi.org/10.1021/jp5106136 es_ES
dc.description.upvformatpinicio 6819 es_ES
dc.description.upvformatpfin 6827 es_ES
dc.type.version info:eu repo/semantics/publishedVersion es_ES
dc.description.volume 119 es_ES
dc.description.issue 12 es_ES
dc.relation.senia 305257 es_ES


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