Gold Nanoshells: Synthesis and Applications to In Situ SERS

In situ surface-enhanced Raman spectroscopy (SERS) is a powerful technique for probing molecular adsorption and reaction at the solid-liquid interface due to its very high surface sensitivity, wide applicable frequency range, and relative insensitivity to water. However, a low SERS activity and poor uniformity of roughened Au electrodes hinder further applications in the solid-liquid interfacial analysis and Pt-group electrocatalysis for fuel cells. The interaction between Nafion and catalysts are of importance for the fuel cell development, but it has not been adequately addressed. Investigating the adsorption structure of Nafion at the Pt/electrolyte interface can lead to better understanding of the stability and efficiency of catalysts, as well as the proton conducting mechanism. It is significant to design a new SERS active electrode with an excellent enhancement and good uniformity, so that rich vibrational information of Nafion adsorbed on Pt catalysts can be obtained. In this dissertation, SiO2@Au core shell nanoparticles with tunable optical properties were employed as SERS active electrodes to achieve these goals. The core shell nanoparticles with optimal Raman enhancement were synthesized and then assembled to form a nanoshell array/glassy carbon electrode for in situ SERS. Some fundamental issues critical to understanding the nanoshell synthesis mechanism were also addressed. By using the new SERS electrode, the interfacial adsorption structure of Nafion on Pt catalysts and its effect on the Pt catalytic activity were addressed. Alkanesulfonate adsorption on Au electrodes was also studied to aid the understanding of Nafion adsorption. A new technique combining rotating disk electrode (RDE) with nanoshell arrays for in situ SERS studies was developed. The technique allows for obtaining high quality SER spectra free from the photodegradation interference. The efficacy of this new method in mitigating the surface-enhanced photodegradation of the analytes was demonstrated by using several model systems both in air and in the electrochemical interfaces.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Chemistry and Biochemistry

Grantor dc:publisher

Miami University

Year dc:date

2013

Author dc:creator

• Zeng, Jianbo

Contributors dc:contributor

• Zou, Shouzhong
• Sommer, André

• Chemistry
• Au nanoshells
• Raman spectroscopy
• in situ SERS
• electrochemistry
• fuel cell
• Nafion
• photodegredation
• alkanesulfonates

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=miami1362843561

OAI identifier oai:identifier

oai:etd.ohiolink.edu:miami1362843561