Facile Catalyst-Free One-Pot Synthesis and Optical Properties of MgO Nanocrystals with Different Morphologies in Atmospheric Air

Abstract

MgO nanocrystals with cube, wire and flower shapes were fabricated by thermal evaporation technique in air at atmospheric pressure. Mg powder mixed with graphite powder was used as the source material and no catalyst was used in the synthesis process. The morphology of the MgO nanocrystals was significantly changed from cube shape to wire and then flower-like shape with increasing the mass ratio of graphite to Mg in the source material. This indicates that the mass ratio of Mg/graphite in the source material played a crucial role in the morphological change of MgO nanocrystals. All the MgO crystals had a cubic crystal structure. The cube-shaped MgO crystals exhibited a blue emission centered at 420 nm, whereas the wire and flower-shaped MgO crystals showed an ultraviolet emission at 380 nm.

MgO nanocrystals synthesized via thermal evaporation of Mg/graphite powders with different mass ratios of (a) 5:1 and (b) 1:1.