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Los Alamos National LaboratoryCenter for Integrated Nanotechnologies
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2020 Highlights

A selection of CINT science highlights from staff and user research.

CINT Contact  

  • Rohit Prasankumar
  • Nanophotonics and Optical Nanomaterials Thrust
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Plasmonic Nanoparticles Could Hold the Key to Speeding Up Catalytic Reactions

Scientific Achievement

Using ultrafast optical spectroscopy to compare nanoparticles of gold, gold/nickel, and gold/platinum, CINT scientists have shown that the optical properties of these plasmonic nanoparticles are affected by their composition.

Significance and Impact

The alloyed nanoparticles substantially increase carrier relaxation rates. This work could be applied to the design of novel catalysts which can efficiently exploit light for industry-relevant catalytic reactions.

Research Details

TEM images of plasmonic catalyst nanoparticles composed of gold and gold/nickel.
  • Au, Au/Ni, and Au/Pt nanoparticles were fabricated using e-beam evaporation.
  • The TEM images show plasmonic catalyst nanoparticles composed of (a) Au and (b) Au/Ni.
  • Broadband ultrafast optical spectroscopy was used to photoexcite the nanoparticles and measure the corresponding changes in the visible transmission spectrum with femtosecond time resolution.
  • Carrier relaxation was significantly faster in the alloyed nanoparticles, linked to their stronger electron-phonon and phonon-phonon coupling.

Publication: Sim S, Beierle A, Mantos P, McCrory S, Prasankumar RP, Chowdhury S. Ultrafast Relaxation Dynamics in Bimetallic Plasmonic Catalysts. Nanoscale. 2020. [DOI: 10.1039/D0NR00831A]

Funding: This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Los Alamos National Laboratory (Contract DE-AC52-06NA25396) and Sandia National Laboratories (Contract DE-NA-0003525). The authors want to thank the DOE VFP program for a summer scholarship and Ying-Bing Jiang for TEM assistance.