Preparation and thermal stability of the spindle α-Fe2O3@SiO2 core–shell nanoparticles

• The spindle α-Fe2O3@SiO2 nanoparticles (NPs) are successfully prepared by hydrothermal synthesis and modified Stöber method.
• Optical properties are estimated and calculated by UV vis absorption spectrum.
• Thermal stability of the α-Fe2O3, α-Fe2O3@SiO2 and SiO2 NPs are compared and analyzed by the SEM technique.
• The structural changes of α-Fe2O3@SiO2 NPs are measured by XRD measurement.

The spindle α-Fe2O3@SiO2 core–shell nanoparticles (NPs) are prepared via hydrothermal synthesis and modified Stöber method. During these processes, shell thicknesses could be easily adjusted by the amount of tetraethylorthosilicate (TEOS), and the formation of core-free SiO2 could be effectively avoided. The structures and compositions of α-Fe2O3@SiO2 NPs are investigated by transmission electron microscope (TEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV–vis) absorption spectroscopy. These results reveal that the α-Fe2O3@SiO2 NPs with certain sizes are monodisperse and homogeneous. To estimate the thermal stability, the α-Fe2O3, α-Fe2O3@SiO2 and SiO2 NPs are annealed at 600, 800 and 1000 °C for 1 h under air atmosphere, respectively. Furthermore, the stabilities of these NPs are confirmed by thermal analysis methods. The structure and shape stabilities of these as-prepared α-Fe2O3@SiO2 NPs are investigated by XRD and scanning electron microscope (SEM).

Schematic of preparation of the monodisperse spindle α-Fe2O3@SiO2 nanoparticles (NPs).Figure optionsDownload as PowerPoint slide