Regiospecific growth of Au on a concave PtZn nanocube forming an Au–PtZn surface mosaic nanocube and an Au–PtZn octapod

Abstract

Regioselective growth of a heterophase on facet-controlled nanocrystals is an indispensable step towards generation of geometrically well-defined heteronanoarchitectures. The growth of a heterophase usually occurs on the most unstable surface features of a nanoparticle, such as vertices and edges, and therefore the ability to control the surface energy of facet-controlled nanocrystals is crucial for the rational synthesis of nanoarchitectures. It is, however, not easy to attain the ability to regioselectively grow a heterophase on a facet-controlled nanocrystal. Herein we introduce a simple strategy to pinpoint the site of heterophase growth on the surface of a faceted nanocrystal by controlling the concentration of surface-stabilizing moieties. Specifically, we show the regioselective growth of Au on a PtZn concave nanocube, covered with surface-bound CO moieties, forming two completely different Au–PtZn heteronanostructures of a filled-concave Au–PtZn surface mosaic nanocube and a vertex-covered Au–PtZn octapod. We also show their application in surface-enhanced Raman scattering (SERS)-based detection of small molecules.

Multicomponent Plasmonic Nanoparticles: From Heterostructured Nanoparticles to Colloidal Composite Nanostructures

“…157 Regioselective growth of Au on the pointed vertices, concave faces, or PtZn concave nanocubes resulted in three different Au-PtZn nanostructures. 385 Au-PtZn with Au covered on both sites showed the strongest extinction crosssection at the peak maximum and so does the SERS intensity. One can also expect a different catalytic overgrowth tendency and formation chemistry.…”

Rational Synthesis of Heterostructured M/Pt (M = Ru or Rh) Octahedral Nanoboxes and Octapods and Their Structure-Dependent Electrochemical Activity Toward the Oxygen Evolution Reaction

“…Preparation of RUOP and RHOP : A slurry of PtZn concave cube as prepared (20 mg), [ 25 ] M(acac) 3 (M = Ru or Rh; 0.02 mmol), 1,2-hexadecanediol (0.1 mmol), and octadecylamine (15 mmol) was prepared in a 100 mL Schlenk tube. The tube was placed in the oil bath and heated at 90 °C.…”

“…[21][22][23][24] The shape of seed nanocrystal was found to be critical in the formation of the nanobox morphology. When a concave, Zn-doped Pt nanocube [ 25 ] was employed instead of a perfect Pt cube, the growth of Ru occurs over the entire surface of pointed tips ( RUOP) as shown in Figure 2 . We also conducted angle analysis for the RUOP ( Figure S6b and Table S2, Supporting Information).…”

Surface Passivation and Supersaturation: Strategies for Regioselective Deposition in Seeded Syntheses

“…Supersaturation and surface differentiation can then determine the mode of anisotropic growth. Excess surface capping has previously shown the ability to prevent deposition on capped surfaces. ,, Low supersaturation has promoted anisotropic growth, for example, by growing on only one or a few faces of a nanocube. , Combining the two effects should then help to promote highly anisotropic growth at only select sites on a nanocrystal seed. In contrast, at high supersaturation, there are enough monomers to nucleate and then grow at each of the defect-rich sites, preserving the symmetry of the seed when defects are reliably located at symmetry-related vertices of a shape-controlled seed.…”

“…Excess surface capping has previously shown the ability to prevent deposition on capped surfaces. 6,16,17 Low supersaturation has promoted anisotropic growth, for example, by growing on only one or a few faces of a nanocube. 18,19 Combining the two effects should then help to promote highly anisotropic growth at only select sites on a nanocrystal seed.…”