Influence Of Ph On Optical And Structural Properties Of Zinc Oxide Nanoparticels By Hydrothermal Method

In this paper, .zinc oxide nanoparticles of different particle size were successfully synthesized via simple hydrothermal method by controlling the pH parameter. The zinc chloride was used as a transition metal precursor to synthesize the ZnO with the presence of sodium hydroxide. The mixture was heated at 180°C for 24 hours for all samples. The pH of the precursor was varied from 8, 9, 10, 11 and 12 by controlling the amount of sodium hydroxide. The morphological variation and the optical band gap of zinc oxide (ZnO) nanostructures varied by the pH of precursor were studied. The samples were characterized with X-ray diffraction (XRD), Scanning electron microscope (SEM) and Ultraviolet-Visible (UV-Vis) spectroscopy. XRD pattern shows that the ZnO nanostructured exhibit the hexagonal wur.ite structure with the average crystallite size is calculated. The morphology images by SEM revealed the nanorod (ID), spherical granule (2D) and nanoflower (3D) structure for all samples. UV-Vis spectroscopy shows the absorption or reflectance peaks of zinc oxide was around 300 to 400 nm indicates the presence of blueshift. The energy band gap was found to be increase with the pH value. Thus, pH plays a crucial role to the structure control and tuning of band gap.
Keywords: Zinc Oxide, Hydrothermal method, Hexagonal Wurtize.