In this paper, fine, homogeneous, and high purity MgAl2O4 nanopowder was synthesized by a novel facile non-hydrolytic sol-gel (NHSG) route. The spinel powders were characterized by various techniques, such as DTA-TG, XRD, SEM, and TEM. It is found that the formation of pure single-phase spinel MgAl2O4 powder begins at 500 °C due to the obtaining of Mg-O-Al bonds in the gel. No impurity appears at the whole temperature range (from 450 to 750 °C), which is ascribed to the exact stoichiometry of magnesium and aluminium in the bimetallic alkoxides Mg(Al(OEt)3)2 to form MgAl2O4. The average particle size of MgAl2O4 synthesized at 700 °C is about 6.96 nm with high dispersion and crystallinity. NHSG synthesis method from bimetallic alkoxides is expected to be a promising preparation method for the synthesis of compound oxides.
Highlights: A novel nonhydrolytic sol-gel route for MgAl2O4 synthesis is developed.Precursors of bimetallic alkoxides effectively avoid the impurities.The synthesis mechanism is confirmed.