Showing papers by "Qingbo Zhang published in 2009"
TL;DR: The closely matched geometrical attributes of these icosahedral nanoparticles allowed them to easily self-assemble into 3-D superlattices either in the solution phase or on a solid substrate.
Abstract: This paper reports the synthesis and self-assembly of monodisperse icosahedral Ag, Au, and Pd nanoparticles with tunable sizes. Ag nanoparticles were first prepared by a modified polyol method. The as-synthesized Ag nanoparticles were all icosahedral multiply twinned particles (MTPs) with notable size variations. The variability was reduced to less than 5% after a digestive ripening post treatment. The nearly monodisperse Ag nanoparticles were then used in replacement reactions with Au and Pd precursors to produce monodisperse icosahedral Au and Pd nanoparticles. The size of the monodisperse icosahedral Ag, Au, and Pd nanoparticles could also be increased thereafter by seed-mediated growth. The closely matched geometrical attributes of these icosahedral nanoparticles allowed them to easily self-assemble into 3-D superlattices either in the solution phase or on a solid substrate.
179 citations
TL;DR: In this article, a strategy for synthesizing monodisperse Ag-Au alloy nanoparticles whereby particle attributes such as morphology, composition, size, and surface chemistry may be independently controlled, varied, and customized is presented.
Abstract: Here, a strategy for synthesizing monodisperse Ag–Au alloy nanoparticles whereby particle attributes such as morphology, composition, size, and surface chemistry may be independently controlled, varied, and customized is presented. The synthesis uses a multi-step procedure to deliver control of morphology, size, and composition in discrete and independent steps. Specifically Agnanoparticles withthesamemorphologybutdifferentsizesare first prepared by the chemical reduction of Ag ions. A digestive ripening posttreatment followed by seed-mediated growth is then applied to narrow the size distribution and to vary the particle size. Monodisperse Ag–Au alloy nanoparticles are then formed by a replacement reaction with HAuCl4. Both single-crystalline truncated octahedral (TO) Ag–Au alloy nanoparticles and icosahedral multiply twinned particles can be easily prepared by this procedure. By using truncated octahedrons as the model morphology, the syntheses of nanoparticles with the same size but different compositions, of nanoparticles with the same composition but variable sizes, and of nanoparticles with different surface chemistry are demonstrated and discussed in detail. Because of the shape and size monodispersity, all of the as-synthesized Ag–Au alloy nanoparticles easily form superlattices on a solid substrate upon slow evaporation of the solvent. The packing pattern of the nanoparticles is strongly dependent on the native morphology of the nanoparticles.
93 citations
TL;DR: In this article, the authors summarized the work in recent years on the solution synthesis of nanoparticles with tunable optical properties and demonstrated the versatility of colloidal synthesis as a convenient scalable technique for tuning the properties of metallic nanoparticles.
Abstract: Solutions of Ag and Au nanoparticles are strongly colored because of localized surface plasmon resonance in the UV/visible spectral region. The optical properties of these nanoparticles may be tuned to suit the needs of the application. This article summarizes our work in recent years on the solution synthesis of nanoparticles with tunable optical properties. The systems of interest include zero-dimensional bimetallic Ag–Au nanoparticles with different structures, one-, two-, and three-dimensional anisotropic monometallic Ag or Au nanoparticles. All of these nanosystems were prepared from colloidal synthesis through simple changes in the synthesis conditions. This is a demonstration of the versatility of colloidal synthesis as a convenient scalable technique for tuning the properties of metallic nanoparticles.
82 citations
TL;DR: Hollow hybrid PbS(x)-Au nanostructures of about 10 nm in diameter were synthesized using a one-step reaction under mild experimental conditions due to the redox reaction of gold precursors with P bS nanocrystals in the presence of dodecylamine.
Abstract: Bleiernes Gold: Hohle PbSx-Au-Hybridnanostrukturen von etwa 10 nm Durchmesser wurden unter milden experimentellen Bedingungen mithilfe einer einstufigen Reaktion synthetisiert. Die Redoxreaktion von Goldvorstufen mit PbS-Nanokristallen in Gegenwart von Dodecylamin liefert die hohlen Hybridnanostrukturen (siehe Bild).
37 citations
TL;DR: The formation of these porous platinum networks could be rationalized by a mechanism where citrate ions and Chini-like platinum carbonyl clusters formed upon CO exposure are the most important contributors.
Abstract: A simple one-pot template-free synthesis was used to form porous Pt networks from the CO-induced self-organization of monodisperse primary Pt nanoparticles. Spherical, rod-shaped, knot-like, multibranched, and hyperbranched porous networks could be obtained under different conditions through changes in the reaction temperature and citrate ion concentration. The formation of these porous platinum networks could be rationalized by a mechanism where citrate ions and Chini-like platinum carbonyl clusters formed upon CO exposure are the most important contributors.
21 citations