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Resonances of nanoparticles with poor plasmonic metal tips.

Ringe E, DeSantis CJ, Collins SM, Duchamp M, Dunin-Borkowski RE, Skrabalak SE, Midgley PA - Sci Rep (2015)

Bottom Line: However, the heavily damped plasmon resonances of many catalytically active metals (e.g. Pt, Pd) prevent this dual functionality in pure nanostructures.The addition of catalytic metals at the surface of efficient plasmonic particles thus presents a unique opportunity if the resonances can be conserved after coating.The resonances also couple with a dielectric substrate and other nanoparticles, establishing that the full range of plasmonic behavior is observed in these multifunctional nanostructures despite the presence of Pd.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and NanoEngineering, Rice University, 6100 Main St., Houston TX 77005, USA.

ABSTRACT
The catalytic and optical properties of metal nanoparticles can be combined to create platforms for light-driven chemical energy storage and enhanced in-situ reaction monitoring. However, the heavily damped plasmon resonances of many catalytically active metals (e.g. Pt, Pd) prevent this dual functionality in pure nanostructures. The addition of catalytic metals at the surface of efficient plasmonic particles thus presents a unique opportunity if the resonances can be conserved after coating. Here, nanometer resolution electron-based techniques (electron energy loss, cathodoluminescence, and energy dispersive X-ray spectroscopy) are used to show that Au particles incorporating a catalytically active but heavily damped metal, Pd, sustain multiple size-dependent localized surface plasmon resonances (LSPRs) that are narrow and strongly localized at the Pd-rich tips. The resonances also couple with a dielectric substrate and other nanoparticles, establishing that the full range of plasmonic behavior is observed in these multifunctional nanostructures despite the presence of Pd.

No MeSH data available.


Related in: MedlinePlus

EELS of Au/Pd octopods, size dependence of the LSPR energy and plasmoncoupling.(a) Monochromated STEM-EEL spectra at the different positions markedon the right HAADF-STEM images for the same particle tilted 0°and +30°. (b) Correlation between size (face diagonal)and energy of the lowest energy LSPR; the particle shown in a iscircled in red. UV-Vis data from ref. 8(c) HAADF-STEM image of an octopod dimer. (d,e)Reconstructed EFTEM images with a 0.2 eV slit centered at 1.5and 2.3 eV. Scale bars, 50 nm.
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f2: EELS of Au/Pd octopods, size dependence of the LSPR energy and plasmoncoupling.(a) Monochromated STEM-EEL spectra at the different positions markedon the right HAADF-STEM images for the same particle tilted 0°and +30°. (b) Correlation between size (face diagonal)and energy of the lowest energy LSPR; the particle shown in a iscircled in red. UV-Vis data from ref. 8(c) HAADF-STEM image of an octopod dimer. (d,e)Reconstructed EFTEM images with a 0.2 eV slit centered at 1.5and 2.3 eV. Scale bars, 50 nm.

Mentions: The plasmonic behavior of 11 isolated octopods and several aggregates wasanalyzed using STEM-EELS tilt series; spectra from a particle at 0°and +30° are presented in Fig. 2. When thesub-nanometer beam is far from the particle, the signal obtained is simply theenergy spread of the incoming electrons (the zero-loss peak, ZLP), while spectraobtained with the beam close to the particle tips display a broad but intensepeak around 1.5 to 3.0 eV. Reconstructed energy filteredtransmission electron microscopy (EFTEM) images obtained around the mainspectral feature in single and aggregated nanocrystals indicate that a high EELprobability is concentrated at the sharp tips and that nearby particles interact(Fig. 2 and Supplementary Fig. 7). The dominant, bright bonding mode in the dimeroccurs at 1.5 eV and the dark antibonding mode, at2.3 eV, respectively lower and higher in energy than the expectedLSPR energy for single octopods of this size(~1.8–2.0 eV), consistent with plasmonhybridization37.


Resonances of nanoparticles with poor plasmonic metal tips.

Ringe E, DeSantis CJ, Collins SM, Duchamp M, Dunin-Borkowski RE, Skrabalak SE, Midgley PA - Sci Rep (2015)

EELS of Au/Pd octopods, size dependence of the LSPR energy and plasmoncoupling.(a) Monochromated STEM-EEL spectra at the different positions markedon the right HAADF-STEM images for the same particle tilted 0°and +30°. (b) Correlation between size (face diagonal)and energy of the lowest energy LSPR; the particle shown in a iscircled in red. UV-Vis data from ref. 8(c) HAADF-STEM image of an octopod dimer. (d,e)Reconstructed EFTEM images with a 0.2 eV slit centered at 1.5and 2.3 eV. Scale bars, 50 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4663493&req=5

f2: EELS of Au/Pd octopods, size dependence of the LSPR energy and plasmoncoupling.(a) Monochromated STEM-EEL spectra at the different positions markedon the right HAADF-STEM images for the same particle tilted 0°and +30°. (b) Correlation between size (face diagonal)and energy of the lowest energy LSPR; the particle shown in a iscircled in red. UV-Vis data from ref. 8(c) HAADF-STEM image of an octopod dimer. (d,e)Reconstructed EFTEM images with a 0.2 eV slit centered at 1.5and 2.3 eV. Scale bars, 50 nm.
Mentions: The plasmonic behavior of 11 isolated octopods and several aggregates wasanalyzed using STEM-EELS tilt series; spectra from a particle at 0°and +30° are presented in Fig. 2. When thesub-nanometer beam is far from the particle, the signal obtained is simply theenergy spread of the incoming electrons (the zero-loss peak, ZLP), while spectraobtained with the beam close to the particle tips display a broad but intensepeak around 1.5 to 3.0 eV. Reconstructed energy filteredtransmission electron microscopy (EFTEM) images obtained around the mainspectral feature in single and aggregated nanocrystals indicate that a high EELprobability is concentrated at the sharp tips and that nearby particles interact(Fig. 2 and Supplementary Fig. 7). The dominant, bright bonding mode in the dimeroccurs at 1.5 eV and the dark antibonding mode, at2.3 eV, respectively lower and higher in energy than the expectedLSPR energy for single octopods of this size(~1.8–2.0 eV), consistent with plasmonhybridization37.

Bottom Line: However, the heavily damped plasmon resonances of many catalytically active metals (e.g. Pt, Pd) prevent this dual functionality in pure nanostructures.The addition of catalytic metals at the surface of efficient plasmonic particles thus presents a unique opportunity if the resonances can be conserved after coating.The resonances also couple with a dielectric substrate and other nanoparticles, establishing that the full range of plasmonic behavior is observed in these multifunctional nanostructures despite the presence of Pd.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and NanoEngineering, Rice University, 6100 Main St., Houston TX 77005, USA.

ABSTRACT
The catalytic and optical properties of metal nanoparticles can be combined to create platforms for light-driven chemical energy storage and enhanced in-situ reaction monitoring. However, the heavily damped plasmon resonances of many catalytically active metals (e.g. Pt, Pd) prevent this dual functionality in pure nanostructures. The addition of catalytic metals at the surface of efficient plasmonic particles thus presents a unique opportunity if the resonances can be conserved after coating. Here, nanometer resolution electron-based techniques (electron energy loss, cathodoluminescence, and energy dispersive X-ray spectroscopy) are used to show that Au particles incorporating a catalytically active but heavily damped metal, Pd, sustain multiple size-dependent localized surface plasmon resonances (LSPRs) that are narrow and strongly localized at the Pd-rich tips. The resonances also couple with a dielectric substrate and other nanoparticles, establishing that the full range of plasmonic behavior is observed in these multifunctional nanostructures despite the presence of Pd.

No MeSH data available.


Related in: MedlinePlus