Comparative Study of MgO Nanopowders Prepared by Different Chemical Methods

Magnesium oxide (MgO) was synthesized by three different methods: the sol-gel (SG), microwave-assisted sol-gel (MW), and hydrothermal (HT) methods for comparing the influence of the preparation conditions on the properties of the products. The powders were annealed at 450 ?. The samples were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM/HRTEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), BET specific surface area and porosity, photoluminescence, and UV-Vis spectroscopy. The samples consisted mainly of periclase as a crystalline phase, and the MW and HT preparation methods generated particles with higher specific surface areas. The powders had less-defined morphologies and high levels of aggregation. The optical band gaps of the samples were determined from UV DRS, and the photocatalytic activities of the magnesium oxides obtained by the three methods towards the degradation of methyl orange (MO) under UV light irradiation was evaluated.

Automated summary

Magnesium oxide (MgO) was synthesized using sol-gel, microwave-assisted sol-gel, and hydrothermal methods to investigate the effects of preparation conditions on the properties of the products. The samples were characterized using various techniques, such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, etc. The results showed that the MW and HT methods produced MgO particles with higher specific surface areas, but the powders had less-defined morphologies and high levels of aggregation. The photocatalytic activities of the MgO samples towards the degradation of methyl orange under UV light were also evaluated.