Seed-Mediated
Growth of Gold Nanocrystals: Changes
to the Crystallinity or Morphology as Induced by the Treatment of
Seeds with a Sulfur Species
- Publication date
- Publisher
Abstract
We report our observation of changes
to the crystallinity or morphology
during seed-mediated growth of Au nanocrystals. When single-crystal
Au seeds with a spherical or rod-like shape were treated with a chemical
species such as S<sub>2</sub>O<sub>3</sub><sup>2–</sup> ions,
twin defects were developed during the growth process to generate
multiply twinned nanostructures. X-ray photoelectron spectroscopy
analysis indicated that the S<sub>2</sub>O<sub>3</sub><sup>2–</sup> ions were chemisorbed on the surfaces of the seeds during the treatment.
The chemisorbed S<sub>2</sub>O<sub>3</sub><sup>2–</sup> ions
somehow influenced the crystallization of Au atoms added onto the
surface during a growth process, leading to the formation of twin
defects. In contrast to the spherical and rod-like Au seeds, the single-crystal
structure was retained to generate a concave morphology when single-crystal
Au seeds with a cubic or octahedral shape were used for a similar
treatment and then seed-mediated growth. The different outcomes are
likely related to the difference in spatial distribution of S<sub>2</sub>O<sub>3</sub><sup>2–</sup> ions chemisorbed on the
surface of a seed. This approach based on surface modification is
potentially extendable to other noble metals for engineering the crystallinity
and morphology of nanocrystals formed via seed-mediated growth