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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

Statistical analysis of EELS results on a single Au/Pd octopod.(a) NMF spectral factors (plasmon modes and other contributions) andfit of the raw data using the EELS response at the position marked by a“x” in b. (b) Structural model of the8-branched nanocrystal and dark field STEM images at +30, 0, and−30°. (c) Schematic and loadings for theproximal LSPR, representing the contribution of the mode to the overall EELSprobability. (d) Schematic and loadings for the distal LSPR.(e) Spectral factor and loading at 0° for the tail ofthe zero loss peak. (f) Spectral factor and loading at 0°for the interband transition. (Full loadings are available Supplementary Fig. 8.) Scale bars,50 nm. The EELS and STEM images have the same scale for eachtilt.
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f3: Statistical analysis of EELS results on a single Au/Pd octopod.(a) NMF spectral factors (plasmon modes and other contributions) andfit of the raw data using the EELS response at the position marked by a“x” in b. (b) Structural model of the8-branched nanocrystal and dark field STEM images at +30, 0, and−30°. (c) Schematic and loadings for theproximal LSPR, representing the contribution of the mode to the overall EELSprobability. (d) Schematic and loadings for the distal LSPR.(e) Spectral factor and loading at 0° for the tail ofthe zero loss peak. (f) Spectral factor and loading at 0°for the interband transition. (Full loadings are available Supplementary Fig. 8.) Scale bars,50 nm. The EELS and STEM images have the same scale for eachtilt.

Mentions: Contributions from the tail of the ZLP and the unavoidable spectral and spatialoverlap of high order modes make direct analysis of the raw spectra orreconstructed EFTEM images of single particles of limited use. To overcome thisdifficulty we used a blind source separation technique (non-negative matrixfactorization, NMF) to extract individual plasmon resonances in single octopodsand decouple the effects of the excitation energy spread (Figs2 and 3 and Supplementary Figs 8–9)2438. This approach has recently proven useful to extractplasmonic modes in nanorods, bipyramids, and nanocubes243940.


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)

Statistical analysis of EELS results on a single Au/Pd octopod.(a) NMF spectral factors (plasmon modes and other contributions) andfit of the raw data using the EELS response at the position marked by a“x” in b. (b) Structural model of the8-branched nanocrystal and dark field STEM images at +30, 0, and−30°. (c) Schematic and loadings for theproximal LSPR, representing the contribution of the mode to the overall EELSprobability. (d) Schematic and loadings for the distal LSPR.(e) Spectral factor and loading at 0° for the tail ofthe zero loss peak. (f) Spectral factor and loading at 0°for the interband transition. (Full loadings are available Supplementary Fig. 8.) Scale bars,50 nm. The EELS and STEM images have the same scale for eachtilt.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f3: Statistical analysis of EELS results on a single Au/Pd octopod.(a) NMF spectral factors (plasmon modes and other contributions) andfit of the raw data using the EELS response at the position marked by a“x” in b. (b) Structural model of the8-branched nanocrystal and dark field STEM images at +30, 0, and−30°. (c) Schematic and loadings for theproximal LSPR, representing the contribution of the mode to the overall EELSprobability. (d) Schematic and loadings for the distal LSPR.(e) Spectral factor and loading at 0° for the tail ofthe zero loss peak. (f) Spectral factor and loading at 0°for the interband transition. (Full loadings are available Supplementary Fig. 8.) Scale bars,50 nm. The EELS and STEM images have the same scale for eachtilt.
Mentions: Contributions from the tail of the ZLP and the unavoidable spectral and spatialoverlap of high order modes make direct analysis of the raw spectra orreconstructed EFTEM images of single particles of limited use. To overcome thisdifficulty we used a blind source separation technique (non-negative matrixfactorization, NMF) to extract individual plasmon resonances in single octopodsand decouple the effects of the excitation energy spread (Figs2 and 3 and Supplementary Figs 8–9)2438. This approach has recently proven useful to extractplasmonic modes in nanorods, bipyramids, and nanocubes243940.

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