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

Queiroz De Albuquerque, R, Nome, R, Ferbonink, G, Camargo, P, Rodrigues, T and Santos, D Correlating structural dynamics and catalytic activity of AgAu nanoparticles with ultrafast spectroscopy and all-atom molecular dynamics simulations. Faraday Discussions. ISSN 1364-5498 (Accepted)

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Abstract

In this study, we investigated hollow AgAu nanoparticles with the goal of improving our understanding of the compositiondependent catalytic activity of theses 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. Electronphonon 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.

Item Type: Article
Uncontrolled Keywords: 0306 Physical Chemistry (Incl. Structural), 0904 Chemical Engineering
Subjects: Q Science > QD Chemistry
Divisions: Pharmacy & Biomolecular Sciences
Publisher: Royal Society of Chemistry
Date Deposited: 26 Jan 2018 09:43
Last Modified: 26 Jan 2018 09:43
URI: http://researchonline.ljmu.ac.uk/id/eprint/7900

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