Morphosynthesis of Rhombododecahedral Silver Cages by Self-Assembly Coupled with Precursor Crystal Templating

摘要

The self-assembly and higher-order organization of micro- and nanostructured building blocks into complex architectures with hierarchy across extended length scales is a key challenge in current materials synthesis and device fabrication.[1]-[8] In particular, many recent efforts have been devoted to the controlled organization of primary building blocks into hollow spheres or cages,[9]-[14] as these hollow structures with nanometer-to-micrometer dimensions have widespread potential applications, including in catalysis, in drug delivery, as artificial cells, as light fillers, and as photonic crystals.[15] In most cases, however, only spherical hollow structures have been obtained either by using colloidal particles[9] or emulsion droplets[10] as templates, or by direct self-assembly of the primary particles without using external templates.[11]-[13] It is expected that tailoring the external morphology of hollow structures would endow them with unique properties as a consequence of the importance of shape and texture in determining the properties of the materials.[16] It is noteworthy that hexagon-based drums formed by textured self-assembly of ZnO nanocrystals were recently produced in a solid-vapor deposition process involving epitaxial surface oxidation;[14] however, the geometrical shapes of the polyhedral cages are, in general, not well-defined, and such a process could be largely limited to specific oxide systems. Thus, it is desirable to explore feasible methods to organize primary building blocks into hollow cages with well-defined, novel geometrical morphologies.