Effect of Surface Roughness on the Photodissociation Threshold of Chlorobenzene and 3-Chloropyridine Adsorbed on Silver

Myli, K. B.; Grassian, V. H.

doi:10.1021/j100076a001

Cited by 14 publications

(6 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…25 The shifting of the surface plasmon resonance to lower frequencies is advantageous because it allows for the use of lower energy Raman excitation sources. Lower energy excitation reduces the risk of analyte photobleaching 26 and photodegradation 27 and allows for the use of inexpensive, commercially available diode laser sources in the red and NIR spectral region.…”

Section: Introductionmentioning

confidence: 99%

Gold nanorods as surface enhanced Raman spectroscopy substrates for sensitive and selective detection of ultra-low levels of dithiocarbamate pesticides

Saute

Premasiri

Ziegler

et al. 2012

Analyst

131

View full text Add to dashboard Cite

We report the use of gold nanorods as solution-based SERS substrates for the detection of ultralow-levels of three different dithiocarbamate fungicides: thiram, ferbam and ziram. Gold nanorods are attractive to use as SERS substrates due to the ability to tune the surface plasmon resonance of the nanoparticles to the laser excitation wavelength of the Raman spectrometer equipped with a 785 nm diode laser. The gold nanorods are synthesized using a seed-mediated growth method and characterized using UV-Visible spectroscopy, zeta potential, and TEM. The gold nanorods have an aspect ratio of 2.19 ± 0.21 and have an average length of 37.81 ± 4.83 nm. SERS spectra are acquired at different concentrations of each fungicide and calibration curves are obtained by monitoring the intensity of the band arising from the ν(C-N) stretching mode coupled to the symmetric δ(CH(3)) motion. The limits of detection and limits of quantitation are obtained for each fungicide. The limits of detection are 11.00 ± 0.95 nM, 8.00 ± 1.01 nM, and 4.20 ± 1.22 nM for thiram, ferbam, and ziram respectively. The limits of quantitation are 34.43 ± 0.95 nM, 25.61 ± 1.01 nM, and 12.94 ± 1.22 nM for thiram, ferbam, and ziram respectively. It can be seen that the three different dithiocarbamates can be detected in the low nM range based on the limits of detection that are achieved.

show abstract

Section: Introductionmentioning

confidence: 99%

Gold nanorods as surface enhanced Raman spectroscopy substrates for sensitive and selective detection of ultra-low levels of dithiocarbamate pesticides

Saute

Premasiri

Ziegler

et al. 2012

Analyst

131

View full text Add to dashboard Cite

show abstract

“…This has been clearly demonstrated during the last 20 years of studying photodissociation at solid surfaces. [1][2][3][4] Comparable progress has been made for photodissociation in bulk liquids [5][6][7][8][9][10] and in clusters, [11][12][13][14] but the technology to carry out these experiments at liquid surfaces has only recently been developed.…”

Section: Introductionmentioning

confidence: 99%

Photodissociation of ICN at the liquid/vapor interface of chloroform

Vieceli

Chorny

Benjamin

2001

The Journal of Chemical Physics

View full text Add to dashboard Cite

The photodissociation of ICN initially adsorbed at the liquid/vapor interface of chloroform is studied using classical molecular dynamics computer simulations. The photodissociation and subsequent geminate recombination on the ground state of ICN is compared with the same reaction in the bulk liquid. We find that the probability for cage escape at the interface is significantly enhanced due to the possibility that one or both of the photodissociation fragments desorb into the gas phase. The desorption probability is sensitive to the initial location and orientation of the ICN. An examination of the energy disposal into these fragments provides additional information about the competition between geminate recombination and cage escape at the interface.

show abstract

“…The first chamber has been previously described. 22 Briefly, the chamber is equipped with a cylindrical mirror analyzer (CMA), a quadrupole mass spectrometer (QMS), an ion sputter gun, and three gas dosers. The Auger electron and mass spectrometers are interfaced to a PC for data acquisition and analysis.…”

Section: Methodsmentioning

confidence: 99%

Photon-induced reactions of aromatics adsorbed on rough and smooth silver surfaces

Myli¹,

Coon²,

Grassian³

1995

J. Phys. Chem.

Self Cite

View full text Add to dashboard Cite

We have investigated the thermal and photon-induced chemistry of several aromatics adsorbed on smooth and roughened Ag( 11 1) surfaces at low temperatures (1 10 K). Pyrazine, pyridine, 3-chloropyridine, and chlorobenzene quantitatively desorb from Ag( 11 1) near 200 K. After roughening the surface with 2 kV Ar ion bombardment, the breadth of the molecular desorption curves increases, and there is a high-temperature tail due to desorption from defect sites produced by the roughening process. Upon UV photolysis of 1 monolayer, chlorobenzene and 3-chloropyridine photodissociate on smooth and rough Ag surfaces, whereas no detectable photoreactions were observed for pyrazine or pyridine adsorbed on either surface. For the molecules that did undergo photodissociation, a shift to lower energy in the photodissociation threshold was observed on the rough surface relative to the smooth: 3.3 eV versus 3.5 eV for chlorobenzene and 3.5 eV versus 3.9 eV for 3-chloropyridine. We postulate that the decrease in the photodissociation threshold is due to defect sites produced by surface roughening, through either excitation of the surface plasmon resonance, which is allowed on the rough but not the smooth surface, or a more localized excitation near defect sites. Excitation in the molecular absorption band shows that the photodissociation yield is enhanced for 3-chloropyridine and quenched for chlorobenzene on the rough surface relative to the smooth. Theoretical calculations suggest that there is a decrease in the decay rate for 3-chloropyridine and an increase in the decay rate for chlorobenzene on the rough surface compared to the smooth. Differences between the quenching rates for 3-chloropyridine and chlorobenzene may be related to the different molecular orientations of these two molecules on the surface.

show abstract

Effect of Surface Roughness on the Photodissociation Threshold of Chlorobenzene and 3-Chloropyridine Adsorbed on Silver

Cited by 14 publications

References 9 publications

Gold nanorods as surface enhanced Raman spectroscopy substrates for sensitive and selective detection of ultra-low levels of dithiocarbamate pesticides

Gold nanorods as surface enhanced Raman spectroscopy substrates for sensitive and selective detection of ultra-low levels of dithiocarbamate pesticides

Photodissociation of ICN at the liquid/vapor interface of chloroform

Photon-induced reactions of aromatics adsorbed on rough and smooth silver surfaces

Contact Info

Product

Resources

About