Centrifugal Shape Sorting of Faceted Gold Nanoparticles Using an Atomic Plane-Selective Surfactant.
Highly refined shape populations of gold nanoparticles (AuNPs) are important for emerging applications in catalysis, plasmonics, and nanomaterials growth. To date, research efforts have focused on achieving monodisperse shape by synthetic control or postsynthetic processing that relies on centrifugal sedimentation-based sorting schemes where differences in the particle mass and aspect ratios (e.g., rods and spheres) provide a driving force for separation. Here, we present a technique to reversibly modify the sedimentation coefficients of AuNPs possessing different shapes that would otherwise be virtually indistinguishable during centrifugal sedimentation due to their similar densities, masses, and aspect ratios by exploiting the preferential affinity of the surfactant cetyltrimethylammonium bromide (CTAB) for the Au(100) facet. The resulting tailored sedimentation coefficients enable AuNP shape sorting via density gradient centrifugation (DGC). DGC-refined populations of faceted AuNPs are shown to significantly enhance the growth rate of InAs nanowires when used as seed particles, emphasizing the importance of shape control for nanomaterials growth applications.
Timothy P
TP
Tyler
Pin Ann
PA
Lin
⊥Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.
Yuan
Y
Tian
⊥Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.
Hong-Jun
HJ
Gao
Xuan P A
XP
Gao
R Mohan
RM
Sankaran
Mark C
MC
Hersam
density gradient centrifugation; gold nanoparticles; nanowire growth; separation; transmission electron microscopy