Influence of Temperature on the Morphology and Grain Size of Cupric Oxide (CuO) Nanostructures via Solvothermal Method

Abstract

Cupric oxide (CuO) nanostructures have been synthesized successfully through solvothermal chemical route. The influence of temperature on the morphology and the grain size of CuO have been investigated. Phase analysis of synthesized CuO has also been carried out using X-ray diffraction (XRD). XRD peaks showed the monoclinic crystalline phase of CuO nanostructures. The morphology of CuO has been studied by using Scanning Electron Microscope (SEM). SEM images showed the rod-like and sheet-like morphology of CuO. Fourier Transform Infrared (FTIR) spectroscopy has been employed to study the vibrational modes. The FTIR spectra confirmed the stretching vibrations of Cu-O bond. In addition, UV-visible absorption spectra have been implemented to estimate the energy bandgap of the synthesized CuO nanostructures. The energy bandgap of as prepared CuO nanostructures was estimated between 2.0 eV to 2.52 eV. The grain size was found to be increasing with the rise in temperature. The increase in grain size with increasing temperatures causes the reduction in the bandgap, which is attributed to the quantum confinement effect at smaller particle size.