title: Synthesis of silver nanorods by low energy excitation of spherical plasmonic seeds.
abstract: Plasmon excitation of Ag seed particles with 600-750 nm light in the presence of Ag(+) and trisodium citrate was used to synthesize penta-twinned nanorods. Importantly, the excitation wavelength can be used to control the reaction rate and, consequently, the aspect ratio of the nanorods. When the excitation wavelength is red-shifted from the surface plasmon resonance of the spherical seed particles, the rate of Ag(+) reduction becomes slower and more kinetically controlled. Such conditions favor the deposition of silver onto the tips of the growing nanorods as compared to their sides, resulting in the generation of higher aspect ratio rods. However, control experiments reveal that there is only a range of low energy excitation wavelengths (between 600 and 750 nm) that yields monodisperse nanorods. This study further highlights the utility of using wavelength to control the size and shape of growing nanoparticles using plasmon-mediated methods.
authors.affiliation: Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Mark R
authors.initials: MR
authors.lastname: Langille
authors.forename: Chad A
authors.initials: CA
authors.lastname: Mirkin
mesh_terms: D008027:Light; D043942:Nanotubes / Q000737:chemistry*; D010316:Particle Size; D012834:Silver / Q000737:chemistry*; D020349:Surface Plasmon Resonance; D013499:Surface Properties
chemical_list: D012834:Silver