Limits...
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

a) Contour plot of the Raman spectrum in time. b) First and last Raman spectrum. c) pNTP (green) and DMAB (blue) peak area as a function of time. d) Residuals after two‐component MCR. e) Calculated MCR components, component 1 (green) describes 62 % of the variance in the dataset, component 2 (blue) 32 %, resulting in a total of 94 % of the variance explained by the two‐component MCR model. f) MCR scores in time.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4834609&req=5

fig3: a) Contour plot of the Raman spectrum in time. b) First and last Raman spectrum. c) pNTP (green) and DMAB (blue) peak area as a function of time. d) Residuals after two‐component MCR. e) Calculated MCR components, component 1 (green) describes 62 % of the variance in the dataset, component 2 (blue) 32 %, resulting in a total of 94 % of the variance explained by the two‐component MCR model. f) MCR scores in time.

Mentions: The main Raman peaks of pNTP and DMAB are clearly visible in the color plot (Figure 3 a), as well as in the first and last Raman spectra of the series (Figure 3 b). A simple method for tracking the reaction progress is to plot peak areas of reactant and product as a function of time. Figure 3 c shows the results of this approach, for the Raman peaks at 1335 (sym. NO2 stretch)13 and 1440 cm−1 (N=N stretch).14 The main trends are visible: the DMAB signal comes up with time, whereas the pNTP signal appears to be less affected by the reaction and suffers more from SERS‐intensity variations. The noise level in the signals is rather high, most likely due to the noise in the spectra themselves, though peak shifts also contribute to the noise level. This method is sufficient for monitoring the (irreversible) reaction in time, but shows quite some noise in the overall signal.


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)

a) Contour plot of the Raman spectrum in time. b) First and last Raman spectrum. c) pNTP (green) and DMAB (blue) peak area as a function of time. d) Residuals after two‐component MCR. e) Calculated MCR components, component 1 (green) describes 62 % of the variance in the dataset, component 2 (blue) 32 %, resulting in a total of 94 % of the variance explained by the two‐component MCR model. f) MCR scores in time.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig3: a) Contour plot of the Raman spectrum in time. b) First and last Raman spectrum. c) pNTP (green) and DMAB (blue) peak area as a function of time. d) Residuals after two‐component MCR. e) Calculated MCR components, component 1 (green) describes 62 % of the variance in the dataset, component 2 (blue) 32 %, resulting in a total of 94 % of the variance explained by the two‐component MCR model. f) MCR scores in time.
Mentions: The main Raman peaks of pNTP and DMAB are clearly visible in the color plot (Figure 3 a), as well as in the first and last Raman spectra of the series (Figure 3 b). A simple method for tracking the reaction progress is to plot peak areas of reactant and product as a function of time. Figure 3 c shows the results of this approach, for the Raman peaks at 1335 (sym. NO2 stretch)13 and 1440 cm−1 (N=N stretch).14 The main trends are visible: the DMAB signal comes up with time, whereas the pNTP signal appears to be less affected by the reaction and suffers more from SERS‐intensity variations. The noise level in the signals is rather high, most likely due to the noise in the spectra themselves, though peak shifts also contribute to the noise level. This method is sufficient for monitoring the (irreversible) reaction in time, but shows quite some noise in the overall signal.

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