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Separation of time-resolved phenomena in surface-enhanced Raman scattering of the photocatalytic reduction of p-nitrothiophenol.

van Schrojenstein Lantman EM, de Peinder P, Mank AJ, Weckhuysen BM - Chemphyschem (2014)

Bottom Line: We show that it is possible to study effects that occur on different time scales independently without data reduction using the photocatalytic reduction of p-nitrothiophenol as a showcase system.Using this approach a better description of the nanoscale reaction kinetics becomes available, while the short-term variations can be examined separately to examine reorientation and/or diffusion effects.Now such events can be easily separated from the bulk conversion process by making use of this chemometric method.

View Article: PubMed Central - PubMed

Affiliation: Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht (The Netherlands).

No MeSH data available.


Related in: MedlinePlus

Workflow for the chemometric analysis of the time‐resolved SERS spectra measured. A one‐component principal‐component analysis (PCA) is used to create a filter, separating short‐term spectral blinking from reaction kinetics. Both sets of spectra can subsequently be analyzed via multivariate curve resolution (MCR).
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fig1: Workflow for the chemometric analysis of the time‐resolved SERS spectra measured. A one‐component principal‐component analysis (PCA) is used to create a filter, separating short‐term spectral blinking from reaction kinetics. Both sets of spectra can subsequently be analyzed via multivariate curve resolution (MCR).

Mentions: We present here a novel chemometric method based on PCA for time filtering (see Figure 1). Chemical reactions can hereby be separated from short‐term variations, enabling better analysis of either dataset. To present this analysis method, we use a self‐assembled monolayer (SAM) of p‐nitrothiophenol (pNTP) on a flat Au substrate, as illustrated in Figure 2. SERS activity, and related reactivity, is introduced by deposition of Ag nanoparticles, similar to other experiments described in literature.11 The monolayer of pNTP can be reduced to p,p′‐dimercaptoazobisbenzene (DMAB) via photocatalysis over plasmonic nanoparticles, and typically uses green laser excitation and Ag nanoparticles.3, 12 Rather than using green laser excitation, an excitation wavelength of 785 nm is chosen. This excitation excites the coupled plasmons of Au and Ag and gives sufficient enhancement effect to observe dynamics over single nanoparticle hotspots on the flat Au substrate. The choice of this low‐energy excitation wavelength also ensures that the catalytic reaction is sufficiently slow to observe reactivity during the acquisition of 15 000 consecutive 1 s SERS spectra.


Separation of time-resolved phenomena in surface-enhanced Raman scattering of the photocatalytic reduction of p-nitrothiophenol.

van Schrojenstein Lantman EM, de Peinder P, Mank AJ, Weckhuysen BM - Chemphyschem (2014)

Workflow for the chemometric analysis of the time‐resolved SERS spectra measured. A one‐component principal‐component analysis (PCA) is used to create a filter, separating short‐term spectral blinking from reaction kinetics. Both sets of spectra can subsequently be analyzed via multivariate curve resolution (MCR).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4834609&req=5

fig1: Workflow for the chemometric analysis of the time‐resolved SERS spectra measured. A one‐component principal‐component analysis (PCA) is used to create a filter, separating short‐term spectral blinking from reaction kinetics. Both sets of spectra can subsequently be analyzed via multivariate curve resolution (MCR).
Mentions: We present here a novel chemometric method based on PCA for time filtering (see Figure 1). Chemical reactions can hereby be separated from short‐term variations, enabling better analysis of either dataset. To present this analysis method, we use a self‐assembled monolayer (SAM) of p‐nitrothiophenol (pNTP) on a flat Au substrate, as illustrated in Figure 2. SERS activity, and related reactivity, is introduced by deposition of Ag nanoparticles, similar to other experiments described in literature.11 The monolayer of pNTP can be reduced to p,p′‐dimercaptoazobisbenzene (DMAB) via photocatalysis over plasmonic nanoparticles, and typically uses green laser excitation and Ag nanoparticles.3, 12 Rather than using green laser excitation, an excitation wavelength of 785 nm is chosen. This excitation excites the coupled plasmons of Au and Ag and gives sufficient enhancement effect to observe dynamics over single nanoparticle hotspots on the flat Au substrate. The choice of this low‐energy excitation wavelength also ensures that the catalytic reaction is sufficiently slow to observe reactivity during the acquisition of 15 000 consecutive 1 s SERS spectra.

Bottom Line: We show that it is possible to study effects that occur on different time scales independently without data reduction using the photocatalytic reduction of p-nitrothiophenol as a showcase system.Using this approach a better description of the nanoscale reaction kinetics becomes available, while the short-term variations can be examined separately to examine reorientation and/or diffusion effects.Now such events can be easily separated from the bulk conversion process by making use of this chemometric method.

View Article: PubMed Central - PubMed

Affiliation: Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht (The Netherlands).

No MeSH data available.


Related in: MedlinePlus