The electron injection efficiency and the steady state absorptance at different photon energies for a composite system made of Au NPs embedded in a cerium oxide matrix are reported. Cerium oxide can be coupled with plasmonic nanoparticles (NPs) to improve its catalytic properties by visible-light absorption. The present work is a study of the ultrafast dynamics of excited states induced by ultraviolet and visible-light excitation in Au NPs combined with cerium oxide, aimed at understanding the excitation pathways. The data, obtained by femtosecond transient absorption spectroscopy, show that the excitation of localized surface plasmon resonances (LSPRs) in the Au NPs leads to an ultrafast injection of electrons into the empty 4f states of the surrounding cerium oxide. Within the first few picoseconds, the injected electrons couple with the lattice distortion forming a polaronic excited state, with similar properties to that formed after direct band gap excitation of the oxide. At sub-picosecond delay times, we observed relevant differences in the energetics and the time dynamics as compared to the case of band gap excitation of the oxide. Using different pump energies across the LSPR-related absorption band, the efficiency of the electron injection from the NPs into the oxide was found to be rather high, with a maximum above 30%. The injection efficiency has a different trend in energy as compared to the LSPR-related static optical absorptance, showing a significant decrease in low energies. This behavior is explained considering different deexcitation pathways with variable weight across the LSPR band. The results are important for the design of materials with high overall solar catalytic efficiency.

Injecting Electrons into CeO2 via Photoexcitation of Embedded Au Nanoparticles / Spurio, E.; Pelli Cresi, J. S.; Ammirati, G.; Pelatti, S.; Paladini, A.; D'Addato, S.; Turchini, S.; O'Keeffe, P.; Catone, D.; Luches, P.. - In: ACS PHOTONICS. - ISSN 2330-4022. - 10:5(2023), pp. 1566-1574. [10.1021/acsphotonics.3c00184]

Injecting Electrons into CeO2 via Photoexcitation of Embedded Au Nanoparticles

Spurio E.;Pelli Cresi J. S.;Pelatti S.;D'Addato S.;Luches P.
2023

Abstract

The electron injection efficiency and the steady state absorptance at different photon energies for a composite system made of Au NPs embedded in a cerium oxide matrix are reported. Cerium oxide can be coupled with plasmonic nanoparticles (NPs) to improve its catalytic properties by visible-light absorption. The present work is a study of the ultrafast dynamics of excited states induced by ultraviolet and visible-light excitation in Au NPs combined with cerium oxide, aimed at understanding the excitation pathways. The data, obtained by femtosecond transient absorption spectroscopy, show that the excitation of localized surface plasmon resonances (LSPRs) in the Au NPs leads to an ultrafast injection of electrons into the empty 4f states of the surrounding cerium oxide. Within the first few picoseconds, the injected electrons couple with the lattice distortion forming a polaronic excited state, with similar properties to that formed after direct band gap excitation of the oxide. At sub-picosecond delay times, we observed relevant differences in the energetics and the time dynamics as compared to the case of band gap excitation of the oxide. Using different pump energies across the LSPR-related absorption band, the efficiency of the electron injection from the NPs into the oxide was found to be rather high, with a maximum above 30%. The injection efficiency has a different trend in energy as compared to the LSPR-related static optical absorptance, showing a significant decrease in low energies. This behavior is explained considering different deexcitation pathways with variable weight across the LSPR band. The results are important for the design of materials with high overall solar catalytic efficiency.
2023
10
5
1566
1574
Injecting Electrons into CeO2 via Photoexcitation of Embedded Au Nanoparticles / Spurio, E.; Pelli Cresi, J. S.; Ammirati, G.; Pelatti, S.; Paladini, A.; D'Addato, S.; Turchini, S.; O'Keeffe, P.; Catone, D.; Luches, P.. - In: ACS PHOTONICS. - ISSN 2330-4022. - 10:5(2023), pp. 1566-1574. [10.1021/acsphotonics.3c00184]
Spurio, E.; Pelli Cresi, J. S.; Ammirati, G.; Pelatti, S.; Paladini, A.; D'Addato, S.; Turchini, S.; O'Keeffe, P.; Catone, D.; Luches, P.
File in questo prodotto:
File Dimensione Formato  
AuCeFASTacsphotonics.pdf

Open access

Tipologia: Versione pubblicata dall'editore
Dimensione 4.33 MB
Formato Adobe PDF
4.33 MB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

Licenza Creative Commons
I metadati presenti in IRIS UNIMORE sono rilasciati con licenza Creative Commons CC0 1.0 Universal, mentre i file delle pubblicazioni sono rilasciati con licenza Attribuzione 4.0 Internazionale (CC BY 4.0), salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11380/1322628
Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus 3
  • ???jsp.display-item.citation.isi??? 3
social impact