Synthesis and Characterization of Monodisperse Magnetite Nanoparticles by Hydrothermal Method
Monodisperse nanoparticles are materials that are not agglomerate. The good characteristic of these materials is the dispersity in water, so they can better react with target pollutants. Accordingly, in this work, the monodisperse magnetite nanoparticles with the superparamagnetic property were synthesized and characterized. The hydrothermal method with the iron compound and polymer as precursors was conducted. The magnetic nanoparticles were characterized by several techniques including X-ray diffraction, field emission scanning electron microscope, transmission electron microscope, and vibrating sample magnetometer. The saturation magnetization (Ms) value, the coercivity (Hc), and the retentivity (Mr) were measured to demonstrate the paramagnetic behavior of the monodisperse magnetite nanoparticles. The results showed that the Fe3O4 nanoparticle were obtained at 200 °C for 16 h. The particles are monodispersed with the size approximately in the range of 60 - 250 nm as confirmed by FE-SEM and TEM images. These are the single grain and had the spherical shape similar to a blackberry. The saturation magnetization of 17.287 emu/g and ratio of retentivity to saturation magnetization (Mr/Ms) characterized the squareness of the hysteresis loops was 0.03653. It can be indicated that the Fe3O4 nanoparticles had superparamagnetic behavior. This property of Fe3O4 nanoparticles can draw pollutants to absorb on the surface of these nanomaterials. Then adsorbed pollutants can be easily removed by separating the Fe3O4 materials from water. This technique can be applied further in water treatment and pollutant removal.