A novel route for synthesis and growth formation of metal oxides microspheres: Insights from V2O3 microspheres

Abstract

Highly polydisperse V2O3 solid microspheres with large specific surface area were successfully synthesized via a facile hydrothermal decomposition of VOC2O4 solution. The morphology and composition were characterized by scanning electron microscopy (SEM), Energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). V2O3 microspheres display an obvious Mott phase transition at −128.5 °C (cooling curve) and −114.5 °C (heating curve). Some parameters including the reaction temperature, concentration of VOC2O4, reaction time, surfactant, H2C2O4 and precursor were briefly discussed to reveal the formation of V2O3 microspheres. It was found that the precursor is crucial for the fabrication of microsphere. A self-assembly growth mechanism was suggested to explain the growth process of microspheres and the autogenic CO and CO2 gas served as the soft templates. Furthermore, this route was developed to synthesize different metal oxides microspheres, and it was found that AlO(OH), Fe3O4, Fe2O3, Co3O4, Cr2O3, MoO2 and WO3 microspheres were obtained. All the results showed this process was successfully explored as a methodology to synthesize different metal oxides microspheres using the gas as the templates by this facile hydrothermal route.