Encapsulation and Ostwald Ripening of Au and Au-Cl Complex Nanostructures in Silica Shells

• Published in: Advanced functional materials Vol. 16; no. 13; pp. 1679 - 1684
• Main Authors: Lou, X. W., Yuan, C., Rhoades, E., Zhang, Q., Archer, L. A.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 05.09.2006; WILEY‐VCH Verlag
• Subjects: Core/shell particles; Gold; Hollow materials; inorganic; metal; Nanoparticles; Nanoparticles, metal; Nanostructures; Nanostructures, inorganic; Platinum; Silica
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.200500909

We report a general template strategy for rational fabrication of a new class of nanostructured materials consisting of multicore shell particles. Our approach is demonstrated by encapsulating Au or Pt nanoparticles in silica shells. Other superstructures of these hollow shells, like dimers, trimers, and tetramers can also be formed by nanoparticle‐mediated self‐assembly. We have also used the as‐prepared multicore Au–silica hollow particles to perform the first studies of Ostwald ripening in confined microspace, in which chloride was found to be an efficient mediating ligand. After treatment with aqua regia, Au–Cl complex is formed inside the shell, and is found to be very active under in situ transmission electron microscopy observations while confined in a microcell. This aspect of the work is expected to motivate further in situ studies of confined crystal growth. A general template strategy (see figure) has been developed for fabrication of a new class of nanostructured materials consisting of Au (Pt)–silica multicore shell particles, which are suitable for studies of Ostwald ripening in confined microspaces and in situ observation of particle growth. This work is expected to motivate further in situ studies of confined crystal growth, while the materials are promising for use in controlled delivery of therapeutics and as building blocks for photonic crystals.