Additive-Free Synthesis of (Chiral) Gold Bipyramids from Pentatwinned Nanorods.

ABSTRACT: The production of colloidal metal nanostructures with complex geometries usually involves shape-directing additives, such as metal ions or thiols, which stabilize high-index facets. These additives may however affect the nanoparticles' surface chemistry, hindering applications, e.g., in biology or catalysis. We report herein the preparation of gold bipyramids with no need for additives and shape yields up to 99%, using pentatwinned Au nanorods as seeds and cetyltrimethylammonium chloride as surfactant. For high-growth solution:seed ratios, the bipyramids exhibit an unusual "belted" structure. Three-dimensional electron microscopy revealed the presence of high-index {117}, {115}, and {113} side facets, with {113} and {112} facets at the belt. Belted bipyramids exhibit strong near-field enha

SUBMITTER: Bevilacqua F 

PROVIDER: S-EPMC11539099 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature