{"id":{"repo_id":"wustl","oai_identifier":"oai:openscholarship.wustl.edu:etd-1882"},"canonical_url":"https://search.dev.ndltd.org/etd/wustl/oai:openscholarship.wustl.edu:etd-1882","repository":{"repo_id":"wustl","name":"Washington University in St. Louis","base_url":"https://openscholarship.wustl.edu/do/oai/"},"display":{"title":"Design and Synthesis of Nanomaterials for Surface-Enhanced Raman Scattering, Fuel Cell Technology, and Photonics","abstract":"In the first part of my dissertation, I developed two approaches for selectively probing the SERS activities of individual hot spots, i.e., experimentally detect the SERS signals only for the molecules that are trapped within the hot-spot region in individual Ag nanoparticle dimers. Then, I performed a systematic investigation on the SERS activity of individual dimers composed of two closed spaced Ag nanoparticles. By utilizing Ag nanoparticles displaying a variety of well-defined shapes, sizes and orientations to construct the dimers, I were able to precisely correlate the detected SERS signals to the specific geometry of individual hot spots. In the second part of this dissertation, I performed a systematic investigation on the galvanic replacement reaction between PtCl62- and Pd nanocrystals with well-defined shapes including octahedra, nanocubes, and nanorods. The resultant hollow Pd-Pt bimetallic nanostructures were employed as electrocatalysts for the oxygen reduction reaction: ORR). Our results demonstrated that the nanostructures derived from Pd octahedra displayed the highest ORR activity, being 1.7 times more active based on equivalent Pt mass than the commercial Pt/C. I also conducted a mechanistic study on the galvanic replacement reaction between AuCl4- and Pd nanorods. Differently from the Pd-Pt system, a new type of hybrid nanostructure in the tadpole shape consisting of a Au head and a Pd tail was obtained due to a localized galvanic replacement mechanism. As an extension of my work to develop new electrocatalysts for the ORR, a template-engaged reaction was utilized for the synthesis of RuSe2+ nanotubes. The RuSe2 nanotubes were active towards the ORR and displayed no loss in activity in the presence of methanol, as opposed to commercial Pt/C. Finally, the template-engaged reaction was applied to the synthesis of Se@MSe: M = Zn, Cd or Pb) colloidal spheres having similar sizes but different compositions. They were utilized as building blocks to obtain 3D photonic crystals via self-assembly. Moreover, superparagametic properties could be obtained via the incorporation of Fe3O4 nanoparticles into the a-Se cores. Taken together, this represents a versatile approach to the synthesis of magnetoactive spheres with similar dimensions but a variety of compositions and properties.","abstract_html":"In the first part of my dissertation, I developed two approaches for selectively probing the SERS activities of individual hot spots, i.e., experimentally detect the SERS signals only for the molecules that are trapped within the hot-spot region in individual Ag nanoparticle dimers. Then, I performed a systematic investigation on the SERS activity of individual dimers composed of two closed spaced Ag nanoparticles. By utilizing Ag nanoparticles displaying a variety of well-defined shapes, sizes and orientations to construct the dimers, I were able to precisely correlate the detected SERS signals to the specific geometry of individual hot spots. In the second part of this dissertation, I performed a systematic investigation on the galvanic replacement reaction between PtCl62- and Pd nanocrystals with well-defined shapes including octahedra, nanocubes, and nanorods. The resultant hollow Pd-Pt bimetallic nanostructures were employed as electrocatalysts for the oxygen reduction reaction: ORR). Our results demonstrated that the nanostructures derived from Pd octahedra displayed the highest ORR activity, being 1.7 times more active based on equivalent Pt mass than the commercial Pt/C. I also conducted a mechanistic study on the galvanic replacement reaction between AuCl4- and Pd nanorods. Differently from the Pd-Pt system, a new type of hybrid nanostructure in the tadpole shape consisting of a Au head and a Pd tail was obtained due to a localized galvanic replacement mechanism. As an extension of my work to develop new electrocatalysts for the ORR, a template-engaged reaction was utilized for the synthesis of RuSe2+ nanotubes. The RuSe2 nanotubes were active towards the ORR and displayed no loss in activity in the presence of methanol, as opposed to commercial Pt/C. Finally, the template-engaged reaction was applied to the synthesis of Se@MSe: M = Zn, Cd or Pb) colloidal spheres having similar sizes but different compositions. They were utilized as building blocks to obtain 3D photonic crystals via self-assembly. Moreover, superparagametic properties could be obtained via the incorporation of Fe3O4 nanoparticles into the a-Se cores. Taken together, this represents a versatile approach to the synthesis of magnetoactive spheres with similar dimensions but a variety of compositions and properties.","abstract_has_math":false,"creators":["Camargo, Pedro"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":"Biomedical Engineering","degree_department":null,"school":null,"contributors":["Younan Xia"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2009,"date_issued":"2009-05-24T07:00:00Z","date_published":"2009-05-24T07:00:00Z","updated_at":"2026-07-24T06:12:48Z","subjects":["Engineering","Biomedical","Chemistry","Inorganic","Materials Science","applications","fuel-cells","nanomaterials","photonic crystals","SERS","synthesis"],"languages":["English (en)"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.7936/K7MK69WB"],"render_values":[{"text":"https://doi.org/10.7936/K7MK69WB","href":"https://doi.org/10.7936/K7MK69WB","code":true}]}]},"links":{"outbound_url":"https://openscholarship.wustl.edu/etd/883","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Younan Xia"]},{"key":"dc:creator","label":"Author","values":["Camargo, Pedro"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2013-05-25T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biomedical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering","Biomedical","Chemistry","Inorganic","Materials Science","applications","fuel-cells","nanomaterials","photonic crystals","SERS","synthesis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English (en)"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://openscholarship.wustl.edu/etd/883"]},{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.7936/K7MK69WB"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["In the first part of my dissertation, I developed two approaches for selectively probing the SERS activities of individual hot spots, i.e., experimentally detect the SERS signals only for the molecules that are trapped within the hot-spot region in individual Ag nanoparticle dimers. Then, I performed a systematic investigation on the SERS activity of individual dimers composed of two closed spaced Ag nanoparticles. By utilizing Ag nanoparticles displaying a variety of well-defined shapes, sizes and orientations to construct the dimers, I were able to precisely correlate the detected SERS signals to the specific geometry of individual hot spots. In the second part of this dissertation, I performed a systematic investigation on the galvanic replacement reaction between PtCl62- and Pd nanocrystals with well-defined shapes including octahedra, nanocubes, and nanorods. The resultant hollow Pd-Pt bimetallic nanostructures were employed as electrocatalysts for the oxygen reduction reaction: ORR). Our results demonstrated that the nanostructures derived from Pd octahedra displayed the highest ORR activity, being 1.7 times more active based on equivalent Pt mass than the commercial Pt/C. I also conducted a mechanistic study on the galvanic replacement reaction between AuCl4- and Pd nanorods. Differently from the Pd-Pt system, a new type of hybrid nanostructure in the tadpole shape consisting of a Au head and a Pd tail was obtained due to a localized galvanic replacement mechanism. As an extension of my work to develop new electrocatalysts for the ORR, a template-engaged reaction was utilized for the synthesis of RuSe2+ nanotubes. The RuSe2 nanotubes were active towards the ORR and displayed no loss in activity in the presence of methanol, as opposed to commercial Pt/C. Finally, the template-engaged reaction was applied to the synthesis of Se@MSe: M = Zn, Cd or Pb) colloidal spheres having similar sizes but different compositions. They were utilized as building blocks to obtain 3D photonic crystals via self-assembly. Moreover, superparagametic properties could be obtained via the incorporation of Fe3O4 nanoparticles into the a-Se cores. Taken together, this represents a versatile approach to the synthesis of magnetoactive spheres with similar dimensions but a variety of compositions and properties."]},{"key":"dc:title","label":"Title","values":["Design and Synthesis of Nanomaterials for Surface-Enhanced Raman Scattering, Fuel Cell Technology, and Photonics"]}]}],"canonical_facts":{"dc:contributor":["Younan Xia"],"dc:creator":["Camargo, Pedro"],"dc:date.available":["2013-05-25T07:00:00Z"],"dc:description.abstract":["In the first part of my dissertation, I developed two approaches for selectively probing the SERS activities of individual hot spots, i.e., experimentally detect the SERS signals only for the molecules that are trapped within the hot-spot region in individual Ag nanoparticle dimers. Then, I performed a systematic investigation on the SERS activity of individual dimers composed of two closed spaced Ag nanoparticles. By utilizing Ag nanoparticles displaying a variety of well-defined shapes, sizes and orientations to construct the dimers, I were able to precisely correlate the detected SERS signals to the specific geometry of individual hot spots. In the second part of this dissertation, I performed a systematic investigation on the galvanic replacement reaction between PtCl62- and Pd nanocrystals with well-defined shapes including octahedra, nanocubes, and nanorods. The resultant hollow Pd-Pt bimetallic nanostructures were employed as electrocatalysts for the oxygen reduction reaction: ORR). Our results demonstrated that the nanostructures derived from Pd octahedra displayed the highest ORR activity, being 1.7 times more active based on equivalent Pt mass than the commercial Pt/C. I also conducted a mechanistic study on the galvanic replacement reaction between AuCl4- and Pd nanorods. Differently from the Pd-Pt system, a new type of hybrid nanostructure in the tadpole shape consisting of a Au head and a Pd tail was obtained due to a localized galvanic replacement mechanism. As an extension of my work to develop new electrocatalysts for the ORR, a template-engaged reaction was utilized for the synthesis of RuSe2+ nanotubes. The RuSe2 nanotubes were active towards the ORR and displayed no loss in activity in the presence of methanol, as opposed to commercial Pt/C. Finally, the template-engaged reaction was applied to the synthesis of Se@MSe: M = Zn, Cd or Pb) colloidal spheres having similar sizes but different compositions. They were utilized as building blocks to obtain 3D photonic crystals via self-assembly. Moreover, superparagametic properties could be obtained via the incorporation of Fe3O4 nanoparticles into the a-Se cores. Taken together, this represents a versatile approach to the synthesis of magnetoactive spheres with similar dimensions but a variety of compositions and properties."],"dc:identifier":["https://openscholarship.wustl.edu/etd/883"],"dc:identifier.doi":["https://doi.org/10.7936/K7MK69WB"],"dc:language":["English (en)"],"dc:subject":["Engineering","Biomedical","Chemistry","Inorganic","Materials Science","applications","fuel-cells","nanomaterials","photonic crystals","SERS","synthesis"],"dc:title":["Design and Synthesis of Nanomaterials for Surface-Enhanced Raman Scattering, Fuel Cell Technology, and Photonics"],"thesis:degree_discipline":["Biomedical Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T06:12:48Z"}