Propeller-Shaped ZnO Nanostructures Obtained by Chemical Vapor Deposition: Photoluminescence and Photocatalytic Properties

S L Wang,W H Tang,H W Zhu,P G Li

doi:10.1155/2012/594290

Abstract

Propeller-shaped and flower-shaped ZnO nanostructures on Si substrates were prepared by a one-step chemical vapor deposition technique. The propeller-shaped ZnO nanostructure consists of a set of axial nanorod (50 nm in tip, 80 nm in root and 1 μm in length), surrounded by radial-oriented nanoribbons (20–30 nm in thickness and 1.5 μm in length). The morphology of flower-shaped ZnO nanostructure is similar to that of propeller-shaped ZnO, except the shape of leaves. These nanorods leaves (30 nm in diameter and 1–1.5 μm in length) are aligned in a radial way and pointed toward a common center. The flower-shaped ZnO nanostructures show sharper and stronger UV emission at 378 nm than the propeller-shaped ZnO, indicating a better crystal quality and fewer structural defects in flower-shaped ZnO. In comparison with flower-shaped ZnO nanostructures, the propeller-shaped ZnO nanostructures exhibited a higher photocatalytic property for the photocatalytic degradation of Rhodamine B under UV-light illumination.

Highlights

Zinc oxide (ZnO), a remarkable II–VI semiconductor with a wide direct band gap of 3.37 eV and large exciton binding energy of 60 meV at room temperature, has attracted considerable interests due to potential application in photocatalysis [1], sensors [2], light-emitting diodes [3], solar cells [4], and so forth
A variety of ZnO nanostructures such as nanowires [9], nanorings [10], nanorods [11], nanobelts [12], nanosheets [13], and star-shaped nanostructures [14] have been synthesized by a number of techniques, which mainly include the hydrothermal synthesis [15], solutionbased synthesis [16], template-based synthesis [17], chemical vapor deposition (CVD) [18], arc discharge technique [19], and thermal evaporation process [20]
Many works have been reported about the ZnO nanostructures, little information concerning the photocatalytic activity of propeller-shaped ZnO nanostructures was presented in previous studies [21, 22]

Summary

Introduction

Zinc oxide (ZnO), a remarkable II–VI semiconductor with a wide direct band gap of 3.37 eV and large exciton binding energy of 60 meV at room temperature, has attracted considerable interests due to potential application in photocatalysis [1], sensors [2], light-emitting diodes [3], solar cells [4], and so forth. Many strategies have been developed to improve the photocatalytic activity of ZnO nanostructures such as changing the structural and morphological characters (size, shape, and crystalline structure, etc.) [7, 8]. Many works have been reported about the ZnO nanostructures, little information concerning the photocatalytic activity of propeller-shaped ZnO nanostructures was presented in previous studies [21, 22]. Propeller-shaped and flower-shaped ZnO nanostructures were prepared on Si substrates by a one-step chemical vapor deposition technique. The morphology, crystal structure, optical property, and photocatalytic property were studied

Experimental Section

Results and Discussion

Conclusions