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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

STEM-CL spectroscopy of Au/Pd octopods.(a) HAADF-STEM image of a single octopod. (b) Panchromatic-CLimage of the octopod in a. (c) Overlay of panchromatic-CL andHAADF-STEM images from a and b. (d) Spectra obtained atthe positions marked in b. (e) HAADF-STEM image of an octopoddimer. (f) Panchromatic-CL image of the dimer in f. Scalebars, 50 nm.
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f4: STEM-CL spectroscopy of Au/Pd octopods.(a) HAADF-STEM image of a single octopod. (b) Panchromatic-CLimage of the octopod in a. (c) Overlay of panchromatic-CL andHAADF-STEM images from a and b. (d) Spectra obtained atthe positions marked in b. (e) HAADF-STEM image of an octopoddimer. (f) Panchromatic-CL image of the dimer in f. Scalebars, 50 nm.

Mentions: CL provides complementary information to EELS and is especially useful toidentify modes in coupled particles: EELS can excite all LSPRs, while CL onlydetects bright modes. Panchromatic-CL (all energies acquired, Fig. 4) maps clearly show that Au retains plasmonic properties inthe presence of Pd and that modes are localized right at the Pd-rich tips. TheCL spectra obtained at various positions on a single 127 nm octopodpeak around 2 eV, as expected (Fig. 2, Supplementary Fig. 10); this LSPR isa bright dipolar resonance. The STEM-CL map of an octopod dimer shows the brightbonding LSPR with high CL emission at the tips distant from the interparticlegap, this resonance corresponds to the 1.5 eV LSPR in Fig. 2d. Moreover, little emission is observed from theinterparticle gap region, confirming that the LSPR in Fig.2e is a dark antibonding mode and that Pd-rich nanoparticles cancouple akin to their Au counterparts.


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)

STEM-CL spectroscopy of Au/Pd octopods.(a) HAADF-STEM image of a single octopod. (b) Panchromatic-CLimage of the octopod in a. (c) Overlay of panchromatic-CL andHAADF-STEM images from a and b. (d) Spectra obtained atthe positions marked in b. (e) HAADF-STEM image of an octopoddimer. (f) Panchromatic-CL image of the dimer in f. Scalebars, 50 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f4: STEM-CL spectroscopy of Au/Pd octopods.(a) HAADF-STEM image of a single octopod. (b) Panchromatic-CLimage of the octopod in a. (c) Overlay of panchromatic-CL andHAADF-STEM images from a and b. (d) Spectra obtained atthe positions marked in b. (e) HAADF-STEM image of an octopoddimer. (f) Panchromatic-CL image of the dimer in f. Scalebars, 50 nm.
Mentions: CL provides complementary information to EELS and is especially useful toidentify modes in coupled particles: EELS can excite all LSPRs, while CL onlydetects bright modes. Panchromatic-CL (all energies acquired, Fig. 4) maps clearly show that Au retains plasmonic properties inthe presence of Pd and that modes are localized right at the Pd-rich tips. TheCL spectra obtained at various positions on a single 127 nm octopodpeak around 2 eV, as expected (Fig. 2, Supplementary Fig. 10); this LSPR isa bright dipolar resonance. The STEM-CL map of an octopod dimer shows the brightbonding LSPR with high CL emission at the tips distant from the interparticlegap, this resonance corresponds to the 1.5 eV LSPR in Fig. 2d. Moreover, little emission is observed from theinterparticle gap region, confirming that the LSPR in Fig.2e is a dark antibonding mode and that Pd-rich nanoparticles cancouple akin to their Au counterparts.

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