The Role Of Temperature And Polyvinyl Alcohol Concentrations In The Synthesis Of Zinc Oxide Nanoparticles

Abstract

The objective of this thesis is to study the role of temperatures and polyvinyl Alcohol concentrations in the synthesis of zinc oxide nanoparticles (ZnONPs). Zinc oxide nanoparticles weresynthesized using zinc nitrate hex-hydrate (Zn(NO3)2.6H2O)and Polyvinyl Alcohol (PVA) concentrations (1.89M, 2.27M, 3.34M)at 400℃, 500℃, 600℃through wet-chemical precipitation methods. The effect of temperatures and concentrations were characterized using X-Ray Diffraction (XRD), Fourier-Transform Infrared (FT-IR), UV-Vis spectroscopy, Scanning Electron Microscopy (SEM) and Fluorescence Spectroscopy. The XRD results shows that the synthesized ZnONPs have wurtzite hexagonal structure with particles size 22nm, 24.1nm and 28.9nm at annealing temperatures of 400℃, 500℃, and 600℃ respectively. On the other hand, the sizes of ZnO NPs for PVA concentrations 1.89M, 2.27M, and 3.34M were 19.23nm, 21.82nm, and 23.84nm at temperature of 400℃respectively. The FT-IR measurements were carried out to indentify the presence of ZnO and its vibrational modes. The signal appeared around 400-600cm−1was assigned for ZnO stretching vibration. The optical absorption of ZnO NPs of annealing temperatures indicatesred shift as the temperature increases.This characterization also revealed that band-gaps energy of ZnONPswas decreased as the temperatures and concentrations are increased. The morphology of ZnO NPs was characterized by SEM also indicated size increment as the temperature and concentration of PVA increases.