Accession Number : ADA182952

Title :   Surface Enhanced Raman Scattering from OH(-) Adsorbed on a Ag Electrode in Dilute Mg+2 Electrolytes.

Descriptive Note : Technical rept.,

Corporate Author : AMHERST COLL MA DEPT OF CHEMISTRY

Personal Author(s) : Dorain,Paul B

PDF Url : ADA182952

Report Date : 27 Jul 1987

Pagination or Media Count : 21

Abstract : Surface enhanced Raman scattering (SERS) has been used to probe the adsorption of OH(-) on a silver electrode immersed in .01 to .001 M MgC12 containing micromolar quantities of either KMnO4 or dissolved C12. Strong spectra due to adsorbed OH(-), nearly identical to those obtained previously in or = 1M MgC12 solutions, were obtained only if the oxidizing agent present. Besides the O-H stretching modes near 3600/cm, the low frequency modes due to the metal oxygen stretch are observed. A model is proposed in which adsorbed Mg+2 provides positive surface charge densities which are sites for absorbing OH(-). Three distinct absorption sites are predicted which is in accord with the observation of three O-H species during H2 production. These results, together with those previously obtained for alkali halides, indicate that corrosion processes in dilute aqueous media proceed by pathways dependent on the concentration and composition of dissolved salts which strongly affect the surface of water and its derivatives. Keywords: Surface enhanced Raman scattering, Adsorbed, Hydroxides, Magnesium ions.

Descriptors :   *HYDROXIDES, *ALKALI METAL COMPOUNDS, *HALIDES, *ELECTRODES, *SILVER, ABSORPTION, CHARGE DENSITY, CORROSION, DILUTION, ELECTRIC CHARGE, IONS, LIGHT SCATTERING, LIQUIDS, LOW FREQUENCY, MAGNESIUM, OXIDATION, OXYGEN, RAMAN SPECTRA, SITES, STATIC ELECTRICITY, SURFACE WATERS

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE