Investigation of structural and optical characteristics of CuO nanoparticles calcinated at various temperatures

Abstract

Copper oxide nanoparticles (CuO) have been synthesized by utilizing a precipitation approach with copper nitrate (Cu(NO₃)₂.3H₂O) as a precursor and sodium hydroxide as a stabilizing agent at different calcination temperatures i.e. 400, 600, and 800°C. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), UV-Visible spectroscopy (UV-Vis), and photoluminescence spectroscopy (PL) were used to look at the sample’s different characteristics. The XRD analysis show that copper oxide nanoparticles have a monoclinic structure with crystallite sizes increasing with increasing calcination temperature up to 600°C, then decreased at 800°C. Also, with increasing temperature, XRD peaks were observed to become sharper, indicating better crystallinity of the samples. FE-SEM image show that synthesized CuO exhibit a flake-like structure, but on calcination it attained a regular particle like structure. The band gap of the material increased as the crystallite size of the material decreased. Photoluminescence intensity was observed to increase with temperature up-to 600°C and then decreased at 800°C. The temperature at which copper oxide nanoparticles were calcined demonstrated to have a considerable impact on their structural and optical properties. The synthesized copper oxide nanoparticles may be employed in the field of electronics in making transistors, heterojunctions, diodes etc. in optoelectronics devices like solar cells, light emitting diodes and in environmental protection for developing gas sensors.