Investigation of ZnO Nanoparticles Synthesized with Different Concentrations of NaOH for Dielectric and Photocatalytic Applications

Abstract

In this study, ZnO nanoparticles are synthesized for photocatalytic and dielectric applications using precipitation technique. The properties of ZnO nanoparticles are investigated for various sodium hydroxide (NaOH) concentrations. The powder X-ray diffraction (PXRD) method is employed to analyse structural properties. PXRD reveals the decrease in cell volume from 47.92 to 47.73 Å and crystallite size varied from 31.96 to 22.53 nm. The scanning electron microscope (SEM) study explained the morphology and EDS measurements revealed the presence of zinc and oxygen distribution on the surface. Further, the particle size is also calculated to be 62.23 nm, 50.16 nm, 46.86 nm and 47.43 nm respectively. The diffuse reflectance spectroscopy (UV-DRS) study indicates that, as NaOH concentration increases, the optical bandgap of the ZnO nanoparticles decreases from 3.25 eV to 3.12 eV. The PL studies revealed blue emission for all ZnO nanoparticles. I–V measurements indicate improved conductivity for higher concentrations of NaOH. A photocatalyst (as synthesized) is examined in the presence of UV radiation for its ability to photodegrade organic pollutants (Methylene Blue dye) with adsorption capacity of 19.7%, 20.3%, 21.48% and 22.97% respectively. The increased adsorption could be due to the increased surface area of the samples. Further, the dielectric properties of the synthesized nanoparticles, including impedance, dielectric constant, conductivity, dielectric loss, and electric modulus is established and examined. © The Tunisian Chemical Society and Springer Nature Switzerland AG 2025.