Synthesis and characterization of 3D ZnO superstructures via a template-free hydrothermal method

The ZnO microrods and flower-like 3D superstructures have been synthesized via a template-free hydrothermal method. The prepared ZnO samples are characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is found that the flower-like 3D ZnO superstructures can be obtained simply by tuning the volume ratio of Zn(OH)(2)(4-) precursor solution to water, or the volume ratio of ethylene glycol to water. When the Volume ratio of Zn(C)H)(4)(2-) precursor solution to water is 1:7, the flower-like 3D ZnO superstructures are obtained, in which the diameter of an individual pencil-like rod is about 1.0 mu m, and the tip size is several nanometers. While when the volume ratio of Zn(OH)(4)(2-) precursor solution to ethylene glycol (EG) is 1:1. the flower-like 3D ZnO Superstructure consists of hexagonal rods with about 500 nm in diameter. A Plausible formation mechanism of flower-like 3D ZnO superstructures is discussed in detail. (C) 2008 Elsevier B.V. All rights reserved