Publications by authors named "Songyi Ham"

Herein, we report a general synthetic pathway to various shapes of three-dimensional (3D) gold nanoframes (NFs) embedded with a Pt skeleton for structural rigidity. The synthetic route comprises three steps: site-specific (edge and vertex) deposition of Pt, etching of inner Au, and regrowth of Au on the Pt framework. Site-specific reduction of Pt on Au nanoparticles (NPs) led to the high-quality of 3D Au NFs with good structural rigidity, which allowed the detailed characterization of the corresponding 3D metal NFs.

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Silver nanoparticles (NPs) ranging in size from 40 to 100 nm were prepared in high yield by using an improved seed-mediated method. The homogeneous Ag NPs were used as building blocks for 2D assembled Ag NP arrays by using an oil/water interface. A close-packed 2D array of Ag NPs was fabricated by using packing molecules (3-mercaptopropyltrimethoxysilane) to control the interparticle spacing.

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Surface plasmonics of nanomaterials has been one of the main research themes in nanoscience. Spherical and elongated nanoparticles show their corresponding unique optical features mainly depending on the physical dimensions. Here we successfully synthesized Au nanorings having Pt framework (Pt@Au nanorings) with high uniformity through wet-chemistry.

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In this report, we tune the surface plasmonic behavior of Au nanoplates depending on the morphology of the Pt shell in which Pt is considered as a less optically inactive element. We describe the synthesis of flat Au nanoplates coated with Pt via rim-preferential or uniform growth methods. Depending on the site-selective growth of Pt on core Au nanoplates, the aspect ratio of the resulting Au@Pt nanoplates was tunable and their corresponding surface plasmon resonance (SPR) bands were controlled accordingly.

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