Morphology, mechanism and optical properties of nanometer-sized MgO synthesized via facile wet chemical method

In the present study, uniform sized magnesium oxide (MgO) nanostructures with high yield were successively synthesized via a simple wet chemical process under calcination temperatures of 500 and 800 degrees C. The structure analysis was conducted and pure phase formation of MgO was identified by employing X-ray diffractometry. Both SEM and HRTEM measurements were performed to characterize the morphology and particle size of the MgO nanocrystals. The nanosized MgO exhibits an optical band gap value of 5.91 eV as obtained from the UV-visible absorption spectrum using the Tauc equation. The MgO samples produced an intense blue emission at 421 nm upon 300 nm excitation which is closely related to oxygen vacancy defect centers. A plausible mechanism is proposed to understand the formation of the observed MgO nanocrystals on the basis of experimental observations and interpretations. The optical properties of MgO suggest that it could be an exceptional choice for optoelectronic nanodevices. (C) 2014 Elsevier B.V. All rights reserved.