Implantation and Growth of Dendritic Gold Nanostructures on Graphene Derivatives: Electrical Property Tailoring and Raman Enhancement

Abstract

Interfacing electron-rich metal nanoparticles with graphene derivatives can sensitively regulate the properties of the resultant hybrid with potential applications in metal-doped graphene field-effect transistors (FETs), surface-enhanced Raman spectroscopy, and catalysis. Here, we show that by controlling the rate of diffusion and catalytic reduction of gold ions on graphene oxide (GO), dendritic "snowflake-shaped" gold nanostructures (SFGNs) can be templated on graphene. The structural features of the SFGNs and their interfacing mechanism with GO were characterized by microscopic analysis and Raman-scattering. We demonstrate that (a) SFGNs grow on GO-surface via diffusion limited aggregation; (b) SFGN's morphology (dendritic to globular), size (diameter of 150-500 nm and a height of 45-55 nm), coverage density, and dispersion stability can be controlled by regulating the chemiophysical forces; (c) SFGNs enhance the Raman signal by 2.5 folds; and (d) SFGNs act as antireduction resist during GO-SFGN's chemical reduction. Further, the SFGNs interfacing with graphene reduces the apparent band gap (from 320 to 173 meV) and the Schottky barrier height (from 126 to 56 meV) of the corresponding FET.

Palladium nanoparticle-graphene hybrids as active catalysts for the Suzuki reaction

“…3(c)) is higher than that of graphene. Such an enhancement has also been observed in examples of GO [29] and carbon nanotubes [30,31] decorated with metal nanoparticles, indicating a probable chemical interaction or bond between the metal nanoparticles and graphene [29,30]. As the graphene in this study is obtained by chemical reduction of GO, there must be many carbon vacancies and defects [12], which may enhance the interaction between Pd nanoparticles and graphene [32,33].…”

Graphene based metal and metal oxide nanocomposites: synthesis, properties and their applications

“…Au NPs deposited on the surface of graphene have enhanced the Raman signal by a factor of 2.5. 576- 578 An enhancement of 60 has been achieved with Au nanodiscs, which were deposited on mechanically exfoliated single-layer graphene. 579 An even larger enhancement (x 120) could be achieved by depositing Au NPs on single-layer graphene (at excitation 633 nm).…”

Synthesis of hexagonal close-packed gold nanostructures

“…These structures also have interesting properties. To date, researchers have used them to synthesize nanoparticles, but the resulting structures have been mostly spherical 16 or lack good crystallinity 17 .…”