Effects of Calcinations Temperatures on Structural, optical and magnetic properties of MgO nanoflakes and its photocatalytic applications

Abstract

This study investigates the thermal, structural, optical and magnetic properties of MgO nanoflakes prepared by a precipitation method calcined at various temperatures ranging from 600 °C to 1000 °C. The structural properties of the samples studied by X-ray diffraction reveal cubic structure of MgO nanocrystals. Scanning electron microscopy study revealed flakes type morphology. Optical bandgap energy calculated from UV–Visible spectra varied from 5.59eV to 5.62eV, was found to be slightly increased with the increase of calcinations temperatures. Photoluminescence study indicates violet and blue emission arising due to oxygen and Mg vacancies and interstitials. The surface area obtained from BET analysis exhibited a higher surface area for sample calcined at 600 °C. Superparamagnetic behaviour is observed for the samples calcined below 800 °C where as a ferromagnetic response is exhibited at lower field for the samples calcined at higher temperatures. The photocatalytic activity was determined for the samples calcined at 600 °C, 800 °C and 1000 °C from which MgO-600 has shown the excellent photocatalytic potency of 98.1%. This study indicates that the structural, optical, magnetic properties and photocatalytic activity of MgO are significantly affected with the calcinations temperatures.