One-Step Synthesis of CoFe2O4 Nanomaterials by Solvothermal Method

Nano-magnetic CoFe2O4 materials with excellent crystallization and high saturation magnetization were synthesized by solvothermal method using Fe(NO3)3·9H2O and Co(NO3)2·6H2O as raw materials and ethanol solution as solvent, respectively. The effects of solvent ratio, reaction temperature and reaction time on the composition and properties of these nanomaterials were explored. The phase, morphology and magnetism of the CoFe2O4 were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). The specific surface area of CoFe2O4 was measured by N2 adsorption-desorption isotherm and calculated by the Brunauer-Emmett-Teller (BET) method. The results showed that the structure and magnetic properties of the prepared materials were greatly dependent on the synthesis conditions. Under optimal prepared conditions, i.e., reaction temperature of 200 °C, reaction time of 20 h and pure ethanol (EtOH) solvent, favorable CoFe2O4 material with high purity, small particle size, larger specific surface area and outstanding saturation magnetization was obtained. Importantly, this method with the advantages of easy-operation, environment-friendliness, and without the introduction of any precipitant or surfactant exhibits promise for the industry-scale production of nano-magnetic CoFe2O4 material. When the reaction temperature is 200 °C, the reaction time is 20 hours and pure C2H5OH is used as the solvent, the purity of the samples is the highest and the saturation magnetization is large. The method has the advantages of simple operation, mild conditions, environment-friendly, without introducing any alkaline precipitant and surfactant, and without subsequent high-temperature crystallization process. It is expected to realize industrial production.