Attenuation of surface‐enhanced Raman spectroscopy response in gold–platinum core‐shell nanoparticles

Flynn, Nolan T.; Gewirth, Andrew A.

doi:10.1002/jrs.841

Cited by 30 publications

(28 citation statements)

References 59 publications

(47 reference statements)

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“…Furthermore, Flynn and Gewirth have reported that SERS-active points tend to be covered first when depositing other metals on gold nanoparticles. [14] Therefore, we believe that there is little pinhole interference in our experiment, because quite a large amount of copper was deposited on the gold nanoparticles (gold particles: % 12 nm; copper-coated particles: % 20 nm, as shown in Figure 1 of the Supporting Information).…”

Section: Resultsmentioning

confidence: 97%

Surface‐Enhanced Raman Scattering of p‐Aminothiophenol on a Au(core)/Cu(shell) Nanoparticle Assembly

et al. 2005

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Surface-enhanced Raman scattering (SERS) of p-aminothiophenol (PATP) molecules adsorbed onto assemblies of Au(core)/Cu(shell) nanoparticles is reported. We compare it with the SERS spectrum of PATP adsorbed onto gold nanoparticles: both the absolute and relative scattered intensities of various bands in the two spectra are very different. The difference in relative intensity can be ascribed to chemical effects; the chemical enhancement ratio of the two substrates is approximately 3-5. A theoretical analysis based on a charge-transfer model is carried out, which yields a consistent result and shows that the difference in chemical enhancement is mainly due to the state densities and Fermi levels of the substrates. The difference in absolute intensity originates from electromagnetic (EM) enhancement. EM enhancement of Au(core)/Cu(shell) nanoparticles is unlike that of single-component gold or copper SERS-active substrates. The core/shell particle size for optimal enhancement is about 20 nm in the case of a 632.8 nm incident laser (the size ratio of the core and shell layers is about 0.6).

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Section: Resultsmentioning

confidence: 97%

Surface‐Enhanced Raman Scattering of p‐Aminothiophenol on a Au(core)/Cu(shell) Nanoparticle Assembly

et al. 2005

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“…The enhancement factor of surface-enhanced Raman spectroscopy (SERS) is very sensitive to the physical and chemical nature of the Au surface [29]. To evaluate the interactions between the Au and IrO x in the current system, the SERS spectrum of IrO x [m]-Au were measured using the pure Au nanoparticles as a control.…”

Section: Resultsmentioning

confidence: 99%

Enhanced electrochemical evolution of oxygen by using nanoflowers made from a gold and iridium oxide composite

2012

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We report on the synthesis of a composite made from iridium oxide and gold that has a flower-like morphology. The ratio of iridium oxide to gold can be controlled by altering the concentrations of the metal precursors or the pH of the solution containing the reductant citrate. Scanning electron microscopy, transmission electron microscopy, Xray diffraction, X-ray photoelectron spectroscopy, and laser confocal micro-Raman spectroscopy were applied to characterize the structures of the nanoflowers, and a mechanism of their formation was deduced. The nanoflowers display an electrocatalytic activity in an oxygen evolution reaction (OER) that is significantly enhanced compared to bare iridium oxide nanoparticles. The highest turnover frequency for the OER of the new nanoflowers is 10.9 s −1 , which is almost one order of magnitude better than that of the respective nanoparticles. These attractive features are attributed to the high oxidation states of iridium in the nanoflowers which is caused by the transfer of electronic charge from metal oxides to gold, and also to the flower fractal structure which is thought to provide a much more accessible surface than suspensions of the respective nanoparticle.

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“…Flynn and Gewirth prepared Au-Pt core-shell nanoparticles by first reducing Au 3+ and subsequently reducing tetrachloroplatinate ion on the gold particles [19]. The bimetallic sol has been used as substrates for surfaceenhanced Raman scattering (SERS) studies [19,20]. LizMarzan and Philipse have used optically transparent imogolite fibers to stabilize Au-Pt, Au-Ag, and Ag-Pt bimetallic hydrosols.…”

Section: Introductionmentioning

confidence: 99%

“…The polymer-protected particles have been used as catalysts for visible-light-induced hydrogen evolution reaction. Flynn and Gewirth prepared Au-Pt core-shell nanoparticles by first reducing Au 3+ and subsequently reducing tetrachloroplatinate ion on the gold particles [19]. The bimetallic sol has been used as substrates for surfaceenhanced Raman scattering (SERS) studies [19,20].…”

Section: Introductionmentioning

confidence: 99%

“…Gold is very useful as an alloying metal due to its relatively low reactivity. It has been used in conjunction with metals such as palladium [2,3,[6][7][8][9][10][11][12][13][14][15][16][17][18] and platinum [5,9,14,[19][20][21][22][23] for various catalytic reactions. The structure of bimetallic combinations depends mainly on the preparation conditions and the miscibility of the two components.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Bimetallic nanoparticles: A single step synthesis, stabilization, and characterization of Au–Ag, Au–Pd, and Au–Pt in sol–gel derived silicates

Devarajan

Bera

Sampath

2005

Journal of Colloid and Interface Science

176

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Nanobimetallic particles consisting of Au-Pd, Au-Ag, and Au-Pt have been synthesized in a single step by a sol-gel process and stabilized in liquid and solid matrices. Organically modified silicates (Ormosils) that play a dual role of a matrix and of a stabilizer have been used to obtain very stable dispersions in the form of sols, gels, and monoliths. The simultaneous reduction of metal ions leads to either a surface enriched with one component or an alloy type of structure depending on the bimetal combination. The nanometallic dispersions are characterized by absorbance, TEM, XRD, IR, XPS, and CO adsorption studies. The stabilized nanoparticles are found to be good electrocatalysts and the preliminary results on the electrochemical reduction of oxygen are reported.

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Attenuation of surface‐enhanced Raman spectroscopy response in gold–platinum core‐shell nanoparticles

Cited by 30 publications

References 59 publications

Surface‐Enhanced Raman Scattering of p‐Aminothiophenol on a Au(core)/Cu(shell) Nanoparticle Assembly

Surface‐Enhanced Raman Scattering of p‐Aminothiophenol on a Au(core)/Cu(shell) Nanoparticle Assembly

Enhanced electrochemical evolution of oxygen by using nanoflowers made from a gold and iridium oxide composite

Bimetallic nanoparticles: A single step synthesis, stabilization, and characterization of Au–Ag, Au–Pd, and Au–Pt in sol–gel derived silicates

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