Synthesis and Characterization of ZnO Nanoparticles via a Microwave-Assisted Method

Zinc oxide (ZnO) is a semiconductor nanomaterial with an array of morphologies useful

in a number of applications. However, ZnO nanostructure formulation can be a challenge because

of costly, timely, or complex synthesis processes. In this study, ZnO samples were synthesized

using an innovative microwave-assisted method and annealed at 150°C. Samples were characterized

using UV-visible spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray

spectroscopy (EDX), and X-ray diffraction (XRD) to study the optical and structural properties of

the ZnO nanostructures produced. Additionally, the band gaps of the samples were calculated

through application of Tauc’s equation for direct transition. Using spectra from the UV-visible

spectrophotometer, we observed that pH and wavelength of light absorbed by the samples had

a direct relationship. Similarly, from structural analysis techniques we also found that pH had

a direct relationship with nanostructure size. Furthermore, all samples consisted solely of one

morphology nanoparticle and were hexagonal, crystalline structures. Finally, the band gaps of the

ZnO nanoparticles were found to be inversely related to the pH of the sample and length of the

nanoparticle diameter.