Solution-Based Modifications of Template-Grown Nanowires

Open Access
Author:
Laraway, Robert
Area of Honors:
Chemistry
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Raymond Edward Schaak, Thesis Supervisor
  • Ken S Feldman, Honors Advisor
  • Christine Dolan Keating, Faculty Reader
Keywords:
  • Nanowires
Abstract:
The synthesis and modifications of nanoscale solids, which underpin advances in nanoscience and nanotechnology, has been a rapidly growing field of chemistry. Nanoparticles, including nanowires, can be synthesized in a variety of ways. However, hard template electrodeposition has many advantages such as creating multi-segmented nanowires. This thesis research explores new strategies for modifying and expanding the complexity of nanowire materials, including protection/deprotection, crystallinity enhancement, creating a composition gradient, and performing galvanic replacement reactions. Ag nanowires were successfully protected by reacting them with sulfur to produce Ag2S. Any excess sulfur was removed by either heating the sample in tetraethylene glycol (TEG) at 200°C or reacting the wires in toluene. To deprotect the wires, the sulfur was removed by heating the wires in TEG at 300° C for two thirty-minute periods. In other modifications, the crystallinity of Pt nanowires was slightly enhanced by annealing them in TEG at 300°C for 1 hour. Establishing a composition gradient in Au/Ag nanowires was attempted by annealing the wires in TEG at 250°C. However, it was concluded that annealing the Au/Ag nanowires had no effect on the gradient. The metal nanowires modified in these experiments were characterized using powder x-ray diffraction and/or scanning electron microscopy, including elemental mapping.