Synthesis, Structural and Optical Properties of Al-doped ZnO (AZO) Nanoparticles

Abstract

For the environmental remediation and degradation of pollutants the study of advanced materials is rapidly increasing due to large varieties of application. Zinc oxide (ZnO) is a semiconductor with a direct band gap between 3.28-3.30 eV and has a wide range of applications in environmental remediation and degradation of pollutants as a photocatalyst material. The energy band gap of ZnO can be minimized and light absorption increased through doping. Pure and Al-doped ZnO nanoparticles are prepared using the sol-gel method with high-purity Zn(NO₃)₂.6H₂O, Al(NO₃)₂.9H₂O, and Propylene glycol, with varying Al : Zn  ratios (1%, 2%, 3%, 4%, and 5%). The prepared samples are characterized by using Fourier Transform Infrared spectroscopy (FTIR), X-ray Diffraction (XRD), X-ray photoelectron Spectroscopy (XPS) and UV-Vis spectroscopy. The XRD pattern confirms the formation of phase pure Pure and Al-doped ZnO nanoparticles at calcination temperature of 500 °C. The optical band gap of Pure ZnO is found to be 3.2 eV which decreases to 2.7 eV on increasing the doping concentration of Al in ZnO matrix.