Surface enhanced Raman spectroscopy as a molecular probe of electrochemical processes
Abstract
The redox transformations of metal oxide films were studied using SERS and computer simulations. The oxidation of nickel hydroxide films was determined to begin at the electrode surface and continue uniformly toward the outer edge of the film. During the reduction of manganese oxide, spectroscopic evidence for the existence of a previously postulated intermediate was recorded. Adsorbate structural transformations during the electroreduction of nitrobenzene and subsequent reoxidation were examined. The occurrence of intermediates and ring coupling reactions was detected. The use of nonaqueous solvents for SERS-electrochemical experiments was found to be feasible although it was often accompanied by severe interferences such as fluorescence and resonance Raman scattering. The adsorption and desorption of pyridine and CN$\sp-$ at SERS active silver and gold electrodes were studied using a thin-layer flow cell and differential double-layer capacitance measurements. The adsorption rates of pyridine at silver were found to be very dependent on surface roughness whereas CN$\sp-$ was found to be independent. Differences in adsorption and desorption rates were attributed to the differences in the accessibility of "SERS active sites".
Degree
Ph.D.
Advisors
Weaver, Purdue University.
Subject Area
Analytical chemistry
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