Effect of the oxidation time of Zn vapor on the growth of ZnO nanostructure

Abstract

The ZnO nanostructures were synthesized on a gold-coated Si substrate via a simple thermal reduction method from a mixture of ZnO and Al powders as reactants. The synthesis of ZnO nanostructure was performed in a quartz tube at 700oC for 30 min by varying the injection position for oxygen. The oxidation time of Zn vapor was able to be controlled by changing the injection position of oxygen in the reaction tube. The morphology of synthesized ZnO nanostructures was changed from nanorod to nanoplate with increasing the oxidation time of Zn vapor. It was revealed that the size of ZnO cluster formed by oxidation of Zn vapor would play an important role on determining the morphology of ZnO nanostructures. The synthesis mechanism of ZnO nanostructures was proposed. The X-ray diffraction (XRD), transmission electron microscopy (TEM), and Scanning electron microscope (SEM) were used to characterize the synthesized ZnO nanostructures. The synthesized ZnO nanorod was found to be pure single crystalline structure and preferentially oriented in the [001] direction, but synthesized ZnO nano comb and ZnO nano plate was poly crystalline structure.