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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Correlating structural dynamics and catalytic activity of AgAu nanoparticles with ultrafast spectroscopy and all-atom molecular dynamics simulations

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Ferbonink, G. F. [1] ; Rodrigues, T. S. [2] ; dos Santos, D. P. [1] ; Camargo, P. H. C. [2] ; Albuquerque, R. Q. [3] ; Nome, R. A. [1]
Total Authors: 6
[1] Univ Estadual Campinas UNICAMP, Inst Quim, Campinas, SP - Brazil
[2] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Ave Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil
[3] Liverpool John Moores Univ, Sch Pharm & Biomol Sci, Liverpool, Merseyside - England
Total Affiliations: 3
Document type: Journal article
Source: FARADAY DISCUSSIONS; v. 208, p. 269-286, AUG 1 2018.
Web of Science Citations: 0

In this study, we investigated hollow AgAu nanoparticles with the goal of improving our understanding of the composition-dependent catalytic activity of these nanoparticles. AgAu nanoparticles were synthesized via the galvanic replacement method with controlled size and nanoparticle compositions. We studied extinction spectra with UV-Vis spectroscopy and simulations based on Mie theory and the boundary element method, and ultrafast spectroscopy measurements to characterize decay constants and the overall energy transfer dynamics as a function of AgAu composition. Electron-phonon coupling times for each composition were obtained from pump-power dependent pump-probe transients. These spectroscopic studies showed how nanoscale surface segregation, hollow interiors and porosity affect the surface plasmon resonance wavelength and fundamental electron-phonon coupling times. Analysis of the spectroscopic data was used to correlate electron-phonon coupling times to AgAu composition, and thus to surface segregation and catalytic activity. We have performed all-atom molecular dynamics simulations of model hollow AgAu core-shell nanoparticles to characterize nanoparticle stability and equilibrium structures, besides providing atomic level views of nanoparticle surface segregation. Overall, the basic atomistic and electron-lattice dynamics of core-shell AgAu nanoparticles characterized here thus aid the mechanistic understanding and performance optimization of AgAu nanoparticle catalysts. (AU)

FAPESP's process: 15/21366-9 - Hybrid materials containing metal nanoparticles for catalytic applications
Grantee:Pedro Henrique Cury Camargo
Support type: Regular Research Grants
FAPESP's process: 15/26308-7 - Optimization of the physicochemical properties of nano -structured materials for applications in molecular recognition, catalysis and energy conversion/storage
Grantee:Roberto Manuel Torresi
Support type: Research Projects - Thematic Grants
FAPESP's process: 16/23430-9 - Exploring stochastic dynamics of nanomaterials
Grantee:René Alfonso Nome Silva
Support type: Regular Research Grants