Synthesis and Characterization of ZnO Nanostructures Using the Sol-Gel Method

Zinc Oxide is a multifunctional material that has applications in several industries. Its properties as a semiconductor in groups II-VI mean that it has a variable band gap. This makes it useful in applications regarding solar cells, which future researchers in our program will be working towards. In the study, the ZnO nanoparticles were synthesized using the so-gel method. Each researcher created identical samples, with 11 rounds of samples being created using the same procedure at a different pH level. Afterwards, we analyzed our particles to determine differences in crystallinity, band gap, and morphology. These particles were characterized using the Transmission Electron Microscopy (TEM), UV-visible Spectroscopy, X-ray diffraction (XRD), and energy-dispersive X-ray Spectroscopy (EDX). We found that the size and shape of the particles were greatly affected by the changes in pH. Starting with nanoparticles at pH 8, the particles consistently grew in size and at pH 10 and 11 nanorods began to be formed. After the XRD analysis we also determined that all of the samples we created had a hexagonal wurtzite structure. As the pH level of the sample increased we also began to see a drop in band gap due to the higher crystallinity of the larger ZnO nanoparticles.