Composition-dependent electronic energy relaxation dynamics of metal domains as revealed by bimetallic Au144-: XAgx(SC8H9)60 monolayer-protected clusters

Hongjun Zheng, Marcus A. Tofanelli, Christopher J. Ackerson, Kenneth L. Knappenberger

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

We examined the electronic relaxation dynamics for mono and bimetallic Au144-xAgx(SC8H9)60 monolayer-protected clusters (MPCs) using femtosecond time-resolved transient extinction spectroscopy. MPCs provide compositionally well-defined model systems for structure-specific determination of nanoscale electronic properties. Based on pulse-energy-dependent transient extinction data, we quantified electron-phonon coupling constants for three distinct Au144-xAgx(SC8H9)60 MPC samples, where x = 0, 0 < x < 30, and x ∼ 30, as Gx=0 = (1.61 ± 0.1) × 1016 W m-3 K-1, Gx<30 = (1.74 ± 0.1) × 1016 W m-3 K-1 and Gx∼30 = (2.07 ± 0.15) × 1016 W m-3 K-1, respectively. These results reflect a trend of greater electron-phonon coupling efficiency with increasing silver content. Based on these data, we conclude that gold-atom replacement by silver occurs at surface sites of the 114-atom metal core of the MPC. Definitive determinations of functional response to nanoscale "alloy" formation and dopant inclusion are critical to establishing predictive models for the development of materials that feature nanoparticles as active components.

Original languageEnglish (US)
Pages (from-to)14471-14477
Number of pages7
JournalPhysical Chemistry Chemical Physics
Volume19
Issue number22
DOIs
StatePublished - Jan 1 2017

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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