Two-dimensional nanoframes with dual rims

Abstract

The synthesis of highly complex two-dimensional (2D) metal nanoframes remains a great challenge. Synthetic strategies for preparing 2D metal nanoframes are few, and rational and systematic synthetic pathways to more complicated architectures have not yet been reported. Herein, we demonstrate a stepwise synthetic strategy for complex 2D metal nanoframes with a high degree of intricacy; the strategy leads to a variety of shapes, including rings, triangles, hexagons, and tripods with tailorable single or double frames in a single entity. These nanoframes of high homogeneity could be obtained through selective combination of four different chemical toolkits consisting of selective etching and deposition on certain facets, and concentric and/or eccentric regrowth by controlling the mismatches of lattice constants of metals. The resulting nanoframes were highly homogeneous in size and shape and had van der Waals interactions that maximized rim-to-rim contact, allowing them to uniquely self-assemble into large-area superstructures.

Synthesis and Single-Particle Surface-Enhanced Raman Scattering Study of Plasmonic Tripod Nanoframes with Y-Shaped Hot-Zones

“…(V) Concentric growth: Au + ions are homogeneously reduced and deposited around Pt frames. It is noteworthy that the combination of multiple on-demand synthetic steps mirrors the synthetic approaches embraced in total synthesis of complex organic molecules, opening a new avenue to more complicated nanoarchitectures. , As shown in Figure a, we synthesized Au nanoprisms with an edge length of ∼155 ± 8 nm and a thickness of ∼9 ± 1 nm, exhibiting characteristic in-plane dipole and quadrupole modes at ∼1240 and 785 nm, respectively (Figure e) . Transformation of Au nanoprisms to tripods was monitored by time-resolved UV–vis–NIR spectroscopy as the corresponding LSPR features vary depending on shape evolution (Figure S4).…”

Synthesis, Assembly, Optical Properties, and Sensing Applications of Plasmonic Gap Nanostructures

“…In another study, 2D, plate-like, nanoframes with dual rims with circular or linear nanogaps were synthesized by controlling the lattice mismatch and growth kinetics of Au and Pt. [80] AuPt nanoframes, which served as a skeleton, were synthesized by the rim-on deposition of Pt 4+ ions upon selective reduction at the boundary of the Au nanoplates, followed by selective Au-etching in the presence of Pt. Depending on the lattice mismatch, further Au growth on the AuPt nanoframes was achieved in either eccentric or concentric growth patterns.…”

Au Nanorings with Intertwined Triple Rings

“…Similar to ancient convex lenses for fire lighting, where sunlight was concentrated into a small spot, plasmonic nanostructures can trap light at the nanoscale through their intrinsic optical properties. Recently, complex plasmonic nanostructures have become a new paradigm in the field of nanoparticles mainly because of their extraordinary light-trapping ability resulting from strong surface plasmon coupling between different electric dipole sources in a single entity. − Such structures have great potential in a wide range of applications such as surface-enhanced Raman spectroscopy, metamaterials, and bio/chemical sensors. − Localized surface plasmon resonance (LSPR) is a unique optical property of plasmonic nanostructures resulting from collective oscillation of conduction electrons coupled with incident electromagnetic fields. Many recent endeavors have been devoted to fabricating complex plasmonic nanostructures by arranging and overlapping the plasmonic building blocks in a confined space for enhancing and concentrating the LSPR in a small region.…”