Large scale synthesis of porous ZnO hollow structures with tunable diameters and shell thicknesses

Hollow and porous nanostructures have attracted a great deal of attention because of their widespread potential applications, and nanostructures with tunable size are desirable to optimize their properties. Therefore, simple and high yield methods for preparation of nanostructures with tunable sizes have been regarded as pursuing objects. Herein, we report a novel simple method for large scale synthesis of porous ZnO hollow structures with tunable diameters and shell thicknesses. The novel synthesis strategy involves oxidizing Zn spheres and polyhedrons in solid state to form a thin ZnO layer on the surface under low temperature, followed by removal of the Zn cores upon heating. Noticeably, not only can the diameter and shell thickness be respectively tuned, but also the shell thickness can be also easily controlled because of its slow oxidation rate in a solid-phase diffusion process under low temperature. It is obvious that this novel simple method involved here can readily be extended to other metal oxide systems. (C) 2009 Elsevier B.V. All rights reserved.