Show simple item record

dc.contributor.advisorWilkinson, Angus P.
dc.contributor.authorVara, Madeline
dc.date.accessioned2018-05-31T18:11:41Z
dc.date.available2018-05-31T18:11:41Z
dc.date.created2018-05
dc.date.issued2017-12-13
dc.date.submittedMay 2018
dc.identifier.urihttp://hdl.handle.net/1853/59813
dc.description.abstractNew methods for the facile synthesis of palladium nanocrystals were developed, with a focus on reaction conditions amenable to scale-up. A photochemical synthesis of 12-nm Pd cube-like nanocrystals decorated with atomic steps and terraces was achieved at room temperature by using a UV-vis light source to excite and promote the reduction of the metal salt precursor. A one-pot synthesis of 18-nm Pd concave nanocubes was also designed at room temperature. Through careful tuning of reduction kinetics alongside an appropriate selection of reactants, single-crystal seeds were first generated followed by a controlled, seed-mediated growth into concave cubes. Platinum-based nanocrystals were studied using high-resolution in situ electron microscopy. Evaluation of Pd@Pt4L cubes and octahedra revealed a shape-dependence on thermal deformation, with cubes first losing expressed crystal facets and shape before alloying, and octahedra first alloying before losing expressed facets. The energetic rationale for these changes was explained using computational modelling. Platinum cubic, octahedral, and icosahedral nanocages with an average wall thickness of 6 atomic layers were studied to understand their thermal stability through in situ electron microscopy. Results indicated limited durability under thermal stress for all nanocages, with hole enlargement leading to the formation of Pt nanoframes. Enhanced durability may be achieved by more carefully tuning the formation of initial pores on the surface of the nanocages. The broader applications and fundamental understandings derived from these studies for future research is discussed.
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.publisherGeorgia Institute of Technology
dc.subjectNanocrystals
dc.subjectNanocrystal synthesis
dc.subjectPalladium
dc.subjectPlatinum
dc.subjectThermal stability
dc.subjectIn situ electron microscopy
dc.titlePalladium and platinum nanocrystals: Facile synthesis and thermal stability
dc.typeDissertation
dc.description.degreePh.D.
dc.contributor.departmentChemistry and Biochemistry
thesis.degree.levelDoctoral
dc.contributor.committeeMemberZhang, Z. John
dc.contributor.committeeMemberWu, Ronghu
dc.contributor.committeeMemberLin, Zhiqun
dc.contributor.committeeMemberXia, Younan
dc.date.updated2018-05-31T18:11:41Z


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record