Charge transfer in first layer enhanced Raman scattering and surface resistance
Main Article Content
Abstract
Abstract
This article is a revue of surface enhanced Raman scattering (SERS) of molecules adsorbed on roughened silver electrodes and on well-characterized, clean Ag-surfaces in ultra high vacuum (UHV). The resonances of the SERS intensities of pyridine, pyrazine and CN- adsorbed on roughened silver electrodes shift when using different Laser wavelengths. SERS is quenched by pulling the electrodes out of the electrolyte, thus exposing them to oxygen. The resonances are assigned to transient electron transfer within surface complexes, which arise from roughening silver electrodes. For pyridine and pyrazine an electron is transferred from the Fermi level EF of the silver electrode to the lowest unoccupied orbital (LUMO). In the case of CN- the electron is transiently transferred from the highest occupied orbital (HOMO) to EF. The energy difference between EF and the LUMO’s of pyridine and pyrazine has been measured by inverse photoemission, in good agreement with the results of SERS. The distance dependence of SERS at well-characterized surface s in UHV shows an enhancement of about 100 restricted to the first adsorbed monolayer, on top of the long range electromagnetic (EM) enhancement. Electron energy loss spectroscopy (EELS) of pyrazine and pyridine on Ag(111) has detected weak structures assigned to electron transfer. Charge transfer reactions induce surface resistance.
Article Details
Copyright
Authors will be required to fill out the below copyright transfer form during the peer-review process and attach it along with their submission. In return, Knowledge Enterprises Journals grants authors the right to publish and reproduce the unrevised contribution in whole or in part at any time and in any form for any scholarly non-commercial purpose with the condition that all publications of the contribution include a full citation to the journal as published by Knowledge Enterprises Journals.
References
2. Creighton, J. A. Surface enhanced Raman electromagnetic enhancement factors for molecules at the surface of small isolated metal spheres, the determination od adsorbbate orientation from SERS relative intensities Surface Science 1983, 124.
3. Burstein, E.; Chen, Y. J.; Chen, C. Y.; Lundquist, S.; Tosatti, E. “Giant"Raman scattering by adsorbed molecules on metal surfaces. Solid State Communications 1979, 29.
4. Fleischman, M.; Hendra, P. J.; McQillan, A. J. Raman Spectra from Electrode Surfaces J.C.S.Chem.Comm. 1973, 26.
5. Jeanmaire, D. L.; VanDuyne, R. P. Surface Raman spectro-electrochemistry, part 1:heterocyclic aromatic and aliphatic amines adsorbed on the anodiced silver electrode. J.Analytic Electrochemistry 1977, 84.
6. Albrecht, M. G.; Creighton, J. A. Anomalously intense Raman spectra of pyridine at a silver electrode J.American Chemical Society 1977, 99.
7. Chang, R. K.; Furtak, T. E. Surface enhanced Raman scattering New York, 1982.
8. Furtak, D. E.; Trott, G.; Loo, B. Light sattering from the metal/solution interface ,chemial origins. Surface Science 1980, 101.
9. Billmann, J.; Otto, A. Electronic Surface-State Contribution to Surface Enhanced Raman-Scattering. Solid State Communications 1982, 44.
10. Roman-Perez, J.; Ruano, C.; Centeno, S. P.; López-Tocón, I.; Arenas, J. F.; Juan Soto, J.; Otero, J. C. Huge Energy Gain in Metal-to-Molecule Charge Transfer Processes: A Combined Effect of an Electrical Capacitive Enhancement in Nanometer-Size Hot Spots and the Electronic Structure of the Surface Complex. J.Physical Chemistry C 2014, 118.
11. Billman, J.; Otto.A. Charge transfer beween adsorbed cyanide and silver probed by SERS. Surface Science 1984, 138.
12. Otto, A.; Mrozek, I.; Grabhorn, H.; Akemann, W. Surface-Enhanced Raman-Scattering. Journal of Physics-Condensed Matter 1992, 4 (5), 1143-1212.
13. Otto, A. Surface enhanced Raman scattering. J.Raman Spectroscopy 1991, 22.
14. Pettenkofer, C.; Eickmans, J.; Ertürk, Ü.; Otto, A. On the nature of "SERS active sites". Surf.Sci. 1985, 151.
15. Pohl, M.; Pieck, M.; Hanewinkel, C.; Otto, A. A Raman Study of Formic Acid and Surface Formate Adsorbed on Cold-deposited Copper Films. J.Raman Spectroscopy 1996, 2.
16. McIntosh, D. F.; Ozin, G. A.; Messmer, R. P. Inorg.Chemistry 1880, 19.
17. Litorja, M.; Haynes, C. L.; Haes, A. J.; Jensen, T. R.; VanDuyne, R. P. Surface-Enhanced Raman Scattering Detected Temperature Programmed Desorption: Optical Properties, Nanostructure, and Stability of Silver Film over SiO2 nanoshere surfaces. J. Phys. Chem. B 2001, 105.
18. Pettenkofer, C.; Mrozek, I.; Borneman, T.; Otto, A. On the contributionof classical electromagnetic field enhancement to Raman scattering from adsorbateson coldly deposited silver films. Surface Science 1978, 188.
19. Otto, A.; Reihl, B. EELS, Inverse and Direct Photoemission of Pyrazine on Ag(111). Surface Science 1986, 178.
20. Otto, A.; Frank, K. H.; Reihl, B. Inverse Photoemission of Pyridine on Silver(111). Surface Science 1985, 163.
21. Sanda, P. N.; Warlaumont, J. M.; Demuth, J. E.; Tsang, J. C.; Christmann, K.; Bradley, J. A. Surface-enhanced Raman scattering from pyridine on Ag(111). Phys.Rev.Lett. 1980.
22. Campion, A. Spectroscopy without enhancement: pyridine on Ag(111). Journal of Electron Spectroscopy and Related Phenomena 1983, 29.
23. Ertürk, U.; Otto, A. Raman Enhancement for Pyridine on Smooth Silver by Submonolayer Deposition of Silver. Europhysics Letters 1988, 6.
24. Campion, A.; Mullins, D. R. Unenhanced Raman scattering from pyridine adsorbed on stepped and kinked silver surfaces under ultrahigh vacuum. Surface Science 1985, 158.
25. Pockrand, I.; Otto, A. Coverage Dependence of Raman-Scattering from Pyridine Adsorbed to Silver-Vacuum Interfaces. Solid State Communications 1980, 35 (11), 861-865.
26. Dick, L. A.; McFarland, A. D.; Haynes, C. L.; VanDuyne, R. P. *Metal Film over Nanosphere (MFON) Electrodes for Surface-Enhanced Raman Spectroscopy (SERS): Improvements in Surface Nanostructure Stability and Suppression of Irreversible Loss. J. Phys. Chem. B 2002, 106.
27. Grabhorn, H. Der Einfluß atomarer Rauhigkeit auf die oberflächenverstärkte Ramanstreung von Adsorbaten an Silberoberflächen. Heinrich-Heine-Universität, Düsseldorf, 1991.
28. Mrozek, I.; Otto, A. Long-Range and Short-Range Effects in SERS from Silver. Europhysics Letters 1990, 11, 243.
29. Kovacs, G. J.; Loutfy, R. O.; Vincett, P. S.; Jennings, C.; Aroca, R. Distance Dependence of SERS Enhancement Factor from Langmuir-Blodgett Monolayers on Metal Island Films:Evidence for the Electromagnetic Mechanism. Langmuir 1986, 2.
30. Mrozek, I.; Otto, A. SERS - a Long-Range Effect? Applied Physics a-Materials Science & Processing 1989, 49, 389.
31. Rasigni, G.; Varnier, F.; Palmari, J. P.; Mayani, N.; Rasigni, M.; Llebaria, A. Study of surface roughness for thin films of CaF2 deposited on glass substrates. Optics communications 1983, 46.
32. Avouris, P.; Demuth, J. E. Electronic excitations of benzene, pyridine, and pyrazlne adsorbed on Ag(111) J. Chem. Phys. 1981, 76.
33. Bader, M.; Haase, J.; Frank, K.-H.; Puschmann, A.; Otto, A. Orientational Phase Transition in the System Pyridine/Ag(111): A Near-Edge X-Ray-Absorption Fine-Structure Study. Phys.Rev.Lett. 1968, 56.
34. Holzapfel, C.; Akemann, W.; Schumacher, D.; Otto, A. Variations of Dc-Resistance and Sers Intensity During Exposure of Cold-Deposited Silver Films. Surface Science 1990, 227 (1-2), 123-128.