Injecting Electrons into CeO 2 via Photoexcitation of Embedded Au Nanoparticles.

Autor:	Spurio E; Dipartimento FIM, Università degli Studi di Modena e Reggio Emilia, Via G. Campi 213/a, 41125 Modena, Italy.; Istituto Nanoscienze, CNR (NANO-CNR), Via G. Campi 213/a, 41125 Modena, Italy., Pelli Cresi JS; Elettra-Sincrotrone Trieste, 34012 Basovizza, Trieste, Italy., Ammirati G; CHOSE (Centre for Hybrid and Organic Solar Energy), Department of Electronic Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome, Italy.; Istituto di Struttura della Materia - CNR (ISM-CNR), EuroFEL Support Laboratory (EFSL), 00133 Rome, Italy., Pelatti S; Dipartimento FIM, Università degli Studi di Modena e Reggio Emilia, Via G. Campi 213/a, 41125 Modena, Italy.; Istituto Nanoscienze, CNR (NANO-CNR), Via G. Campi 213/a, 41125 Modena, Italy., Paladini A; Istituto di Struttura della Materia - CNR (ISM-CNR), EuroFEL Support Laboratory (EFSL), Monterotondo Scalo 00015, Italy., D'Addato S; Dipartimento FIM, Università degli Studi di Modena e Reggio Emilia, Via G. Campi 213/a, 41125 Modena, Italy.; Istituto Nanoscienze, CNR (NANO-CNR), Via G. Campi 213/a, 41125 Modena, Italy., Turchini S; Istituto di Struttura della Materia - CNR (ISM-CNR), EuroFEL Support Laboratory (EFSL), 00133 Rome, Italy., O'Keeffe P; Istituto di Struttura della Materia - CNR (ISM-CNR), EuroFEL Support Laboratory (EFSL), Monterotondo Scalo 00015, Italy., Catone D; Istituto di Struttura della Materia - CNR (ISM-CNR), EuroFEL Support Laboratory (EFSL), 00133 Rome, Italy., Luches P; Istituto Nanoscienze, CNR (NANO-CNR), Via G. Campi 213/a, 41125 Modena, Italy.
Jazyk:	angličtina
Zdroj:	ACS photonics [ACS Photonics] 2023 May 03; Vol. 10 (5), pp. 1566-1574. Date of Electronic Publication: 2023 May 03 (Print Publication: 2023).
DOI:	10.1021/acsphotonics.3c00184
Abstrakt:	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. Competing Interests: The authors declare no competing financial interest. (© 2023 The Authors. Published by American Chemical Society.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu