| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 607928 | Journal of Colloid and Interface Science | 2013 | 6 Pages |
Different morphologies of Au@Ag nanocrystals have been successfully synthesized using iodide ions in growth solutions consisting of ascorbic acid, NaOH, and CTAB. Without I− ions in growth solution, there were unnoticeable changes in morphology. On the other hand, with addition of I− ions, remarkable changes were observed including formation of hexagonal bipyramidal nanocrystals. Ag+ ions were reduced and deposited on {1 1 1} facets of gold hexagonal nanoplates (GHNs), and hexagonal bipyramidal nanoparticles were formed more quickly in the presence of I− ions than without I− ions. Our studies reveal that I− ion affects the selective growth of Ag onto GHNs. This can be explained by the decrease in the surface redox potential of nanocrystals that occurs by combining with the AgI complex on the metallic surface. These results were confirmed by FESEM images, UV–vis–NIR spectra, and TEM images.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (131 K)Download as PowerPoint slideHighlights► Au@Ag nanocrystals synthesized by controlling the surface chemistry of Au. ► In the absence of iodide ions, hexagonal Ag shells were formed. ► In the presence of Iodide ions, hexagonal bipyramidal Ag shells were formed.
