Understanding the microscopic origin of gold nanoparticle anisotropic growth from molecular dynamics simulations
We use molecular dynamics simulations in order to understand the microscopic origin of the asymmetric growth mechanism in gold nanorods. We provide the first atomistic model of different surfaces on gold nanoparticles in a growing electrolyte solution, and we describe the interaction of the metal wi...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 29(2013), 48 vom: 03. Dez., Seite 14954-61 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2013
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article |
| Zusammenfassung: | We use molecular dynamics simulations in order to understand the microscopic origin of the asymmetric growth mechanism in gold nanorods. We provide the first atomistic model of different surfaces on gold nanoparticles in a growing electrolyte solution, and we describe the interaction of the metal with the surfactants, namely, cetyltrimethylammonium bromide (CTAB) and the ions. An innovative aspect is the inclusion of the role of the surfactants, which are explicitly modeled. We find that on all the investigated surfaces, namely, (111), (110), and (100), CTAB forms a layer of distorted cylindrical micelles where channels among micelles provide direct ion access to the surface. In particular, we show how AuCl2(-) ions, which are found in the growth solution, can freely diffuse from the bulk solution to the gold surface. We also find that the (111) surface exhibits a higher CTAB packing density and a higher electrostatic potential. Both elements would favor the growth of gold nanoparticles along the (111) direction. These findings are in agreement with the growth mechanisms proposed by the experimental groups of Murphy and Mulvaney |
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| Beschreibung: | Date Completed 25.09.2014 Date Revised 04.02.2014 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/la403843n |