Lattice-Mismatch-Induced Twinning for Seeded Growth of Anisotropic Nanostructures

Abstract

Synthesis of anisotropic nanostructures from materials with isotropic crystal structures often requires the use of seeds containing twin planes to break the crystalline symmetry and promote the preferential anisotropic growth. Controlling twinning in seeds is therefore critically important for high-yield synthesis of many anisotropic nanostructures. Here, we demonstrate a unique strategy to induce twinning in metal nanostructures for anisotropic growth by taking advantage of the large lattice mismatch between two metals. By using Au-Cu as an example, we show, both theoretically and experimentally, that deposition of Cu to the surface of single-crystalline Au seeds can build up strain energy, which effectively induces the formation of twin planes. Subsequent seeded growth allows the production of Cu nanorods with high shape anisotropy that is unachievable without the use of Au seeds. This work provides an effective strategy for the preparation of anisotropic metal nanostructures.

Symmetry Breaking by Surface Blocking: Synthesis of Bimorphic Silver Nanoparticles, Nanoscale Fishes and Apples

“…Symmetry breaking driven by the strain energy of growing NPs has been reported for Cu deposition onto Au seeds25 and for binary MNPs made from cubic Pt seeds26. Preparation of diverse nanostructures in bimorphic regrowth has been described by Tsuji et al , where cubes, bipyramids, and platelets were formed from nanorods27.…”

Seed‐Mediated Growth of Colloidal Metal Nanocrystals

“…This phenomenon has been actively explored in the growth of semiconductor thin films. [135] It was shown both theoretically and experimentally that the deposition of Cu on singlecrystal Au seeds favored twinning and anisotropic growth (Figure 16 c-f). [26] Instead, as ac onsequence of the large lattice mismatch between Au and Pt (4.08 %), the Au overlayer exhibited ap olycrystalline structure,w hich led to the formation of penta-twinned Au nanorods (Figure 16 a).…”

The alloying effect and AgCl-directing growth for synthesizing a trimetallic nanoring with improved SERS

“…17 Therefore, researchers have been trying to develop new methods and improve reported ones for controllably preparing noble nanostructures. [26][27][28][29][30][31][32][33][34] Selective etching always follows energy-driven rule. [18][19][20][21][22][23][24][25] Among them, seeded growth and selective etching are very fascinating owing to their multi-functions in generating nanostructures.…”