Finely Tunable Fabrication and Catalytic Activities of Anisotropic Au Nanomaterials and Hollow Multi-Au@SiO2 Nanosystems

H. Yoo
Hallym University,
Korea

Keywords: soft-template, gold nanoparticles, core-shell, silica, nanocatalysis

Summary:

One-dimensional Au nanostructures such as bipyramids and fibers are successfully synthesized in a controllable fashion. Solubilization of specific anions into an aqueous CTAB (cetyltrimethylammonium bromide) or CTAC (cetyltrimethylammonium chloride) solution leads to the formation of rod-shaped micelles and becomes a key shape-directing factor. In addition, unique star-shaped Au multipod nanoparticles (GMN) and core-shell GMN@Pt or GMN@Pd nanoparticles with high surface area have been fabricated. The structural features of each branch in these nanoparticles are finely tuned. The catalytic performances are morphology-dependent and synergistically improved in the bicomponent nanosystems. Spherical nanoparticles (multi-Au@SiO2 NPs) and nanowires (multi-Au@SiO2 NWs) with a core comprising multiple Au nanodots and silica shell are fabricated in high yields through reverse (water-in-oil) microemulsion-based methods. By simple treatments, york-shell multi-Au@SiO2 NPs and peapod-like one-dimensional Au nanoparticles array within hollow silica nanotubes (pp multi-Au@SiO2 NTs) can be successfully synthesized. These hollow multi-Au@SiO2 nanosystems can be used as efficient nanoreactors for fabrication of hybrid nanoparticles assembly and catalysis.