Abstract
The excitation behavior of the quenching of SERS for pyridine and C− at Ag electrodes in the presence of monolayer and submonolayer amounts of underpotentially deposited Pb is presented in this report. Intensity—coverage profiles are presented for the ring-breathing mode of pyridine at 1013 cm− 1and v(Ag—C1) at 235 cm− 1with laser excitation at 4579, 4880, 5145, and 6226 Å. Electromagnetic contributions to the quenching behavior are evaluated by comparison of the experimental quenching profiles with theoretical profiles. Theoretical profiles are calculated from a model described by Murray which predicts electromagnetic enhancement at overlayer-covered metal ellipsoids. The experimental and theoretical profiles are in poor agreement, especially for excitation in the red-wavelength region. A chemical model based on photoassisted charge transfer is proposed to account for the experimental behavior at other excitation wavelengths.
Original language | English (US) |
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Pages (from-to) | 777-785 |
Number of pages | 9 |
Journal | Langmuir |
Volume | 3 |
Issue number | 5 |
DOIs | |
State | Published - Sep 1 1987 |
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Surfaces and Interfaces
- Spectroscopy
- Electrochemistry