Optical and Morphological Properties of ZnO- and TiO2-Derived Nanostructures Synthesized via a Microwave-Assisted Hydrothermal Method

Nosipho Moloto,Suprakas Sinha Ray,Lucky M Sikhwivhilu,Siyasanga Mpelane

doi:10.1155/2012/189069

Abstract

A microwave-assisted hydrothermal method was used to synthesize ZnO and TiO2nanostructures. The experimental results show that the method resulted in crystalline monodispersed ZnO nanorods that have pointed tips with hexagonal crystal phase. TiO2nanotubes were also formed with minimum bundles. The mechanism for the formation of the tubes was validated by HRTEM results. The optical properties of both ZnO and TiO2nanostructures showed characteristics of strong quantum confinement regime. The photoluminescence spectrum of TiO2nanotubes shows good improvement from previously reported data.

Highlights

The fabrication of size- and shape-controlled nanoparticles and their assembly into materials still poses a challenge in the area of nanosciences
The samples were characterized using field emission scanning electron microscopy (FESEM) (Leo, Zeiss), operated at 3–10 kV electron potential difference and equipped with a semiconductor detector that allows for detection of energy dispersive X-rays (EDX)
Crystalline ZnO nanorods and TiO2 one-dimensional structures were successfully synthesized via the microwaveassisted hydrothermal method

Summary

Introduction

The fabrication of size- and shape-controlled nanoparticles and their assembly into materials still poses a challenge in the area of nanosciences. It is an II-VI semiconductor that has a direct wide band gap of 3.37 eV and a large excitonic-binding energy (60 meV) Because of these properties, ZnO has found use in various technological applications including transparent conducting electrodes for solar cells, photocatalysis, surface acoustic devices, UV lasers, and as chemical and biological sensors [11,12,13,14,15]. ZnO has found use in various technological applications including transparent conducting electrodes for solar cells, photocatalysis, surface acoustic devices, UV lasers, and as chemical and biological sensors [11,12,13,14,15] Various methods such as the sol-gel method, hydrothermal process, chemical vapour deposition, and the single-source precursor method have been employed to synthesize different ZnO nanostructures [16,17,18,19]. The optical and morphological properties of ZnO and TiO2 synthesized using the microwave-assisted method are hereby reported

Experimental

Structural Characterization

Optical Characterization

Results and Discussions

Conclusion