Facet-Selective Epitaxial Growth of Heterogeneous Nanostructures of Semiconductor and Metal: ZnO Nanorods on Ag Nanocrystals

Abstract

We demonstrate a new approach for synthesizing Ag-ZnO heterogeneous nanostructures in which single-crystalline ZnO nanorods were selectively grown on {111} rather than {100} facets of single-crystalline Ag truncated nanocubes. We have identified the fine structure of the Ag-ZnO heterostructures and proposed a mechanism indicating that structure match plays a critically important role in this type of facet-selective growth. These heterogeneous nanostructures are of special interest and have potential applications in electrical contacts, functional devices, biological sensors, and catalysis.

One-dimensional ZnO nanostructures: Solution growth and functional properties

“…23(b) [239]. Using Ag nanocubes as the nano-substrate, ZnO selectively nucleated and grew on the eight {111} facets.…”

“…The other is the direct interface of the Zn layer with Ag that initiates the formation of the ZnO lattice. Convergent beam electron diffraction studies showed that Zn atoms were the first layer bonded to the surface of the Ag seeds and the growth front of the nanorod was an oxygen layer [239].…”

“…The basic working principle of electrophoretic deposition is that charged nanoparticles (in a colloidal solution) will be [238]. (b) SEM images showing the selective growth of ZnO nanowire branches on the {111} facets of Ag truncated nanocubes, where the yellow and cyan planes represent the {111} and {100} facets of Ag, respectively; the green planes represent the facets of the ZnO nanowires [239]. (c) Low magnification TEM image of a Au-decorated ZnO nanowire [241].…”

Nanocomposites of Ag2S and Noble Metals

“…[23] Subsequently, various approaches were developed for the synthesis of semiconductor-metal nanocomposites (e.g. ZnO-Ag, [24,25] CdS-Au, [26,27] InAs-Au, [28] TiO 2 -Co, [29] PbSAu, [30][31][32][33][34] Ag 2 S-Au, [35] and semiconductor-Pt systems [36][37][38][39] ) by anisotropic growth of metals on semiconductors through reduction, physical deposition, or photochemistry.We recently presented a general protocol for transferring the transition-metal ions from water to an organic medium using an ethanol-mediated method, which was extended to synthesize a wide variety of heterogeneous semiconductornoble-metal nanocomposites. [40] In another study, we synthesized three different types of semiconductor-Au nanocomposites (CdS-Au, CdSe-Au, and PbS-Au), which displayed attractive catalytic activities in the three-component coupling reaction of benzaldehyde, piperidine, and phenylacetylene in water.…”

Physical Confinement Promoting Formation of Cu2O–Au Heterostructures with Au Nanoparticles Entrapped within Crystalline Cu2O Nanorods

“…This growth mechanism is in contrast to reports of nanorods grown epitaxially from single nanoparticles or nanoparticles that are epitaxially nucleated on the surfaces of nanorods. [67][68][69][70] Recent in situ AFM studies of the entrapment of polymeric micelles within calcite crystals has shown that the micelles bind preferentially to the step edges, which then experience little or no inhibition as the calcite lattice grows around the adsorbed micelles. 71 Further, the relatively compliant micelles experience lateral compression as they are occluded in the crystal, where this distortion gives rise to a cavity within the calcite.…”