Preparation And Research Of Nano Fe₃O₄/Graphene （OXIDE） Composites

Since graphene discovered, it is widely used in various fields because of its unique structure and excellent performance. Researchers combine graphene and magnetic particles into magnetic composites. It is widely used in bio separation, pharmaceutical drug targeting, lithium ion battery, electromagnetic absorption. At first, the optimum conditions of the preparation of Fe3O4 nanoparticles was found, the stable water-based magnetic fluid was prepared and research related to performance lately. Finally, the hyperthermia of Fe3O4/graphene oxide in external magnetic field and the application of nanometer Fe3O4/graphene in lithium battery were analyzed.The contents and results are as follows:1、Oleic acid as surfactant, the results of orthogonal experiment shows that the effect of the average particle size:Fe2+and Fe3+molar ratio> reaction temperature>reaction time>the amount of oleic acid, the optimal experiment conditions of preparation Fe3O4 particles is:Fe2+: Fe3+ molar ratio of 1:1.5, reaction time of 90 min, the reaction temperature is 90, oleic acid content of 2.0mL. The size of Fe3O4 nanoparticles is about 10nm, nearly spherical structure, magnetic saturation intensity is 66.35emu/g, remanence 1.35emu/g.2、Water-based magnetic fluid were prepared. The density of water-based magnetic fluid increases with the increase of Fe3O4; the hyperthermia temperature rises with the increase of Fe3O4.3、Graphene oxide and graphene were prepared by the natural graphite through of Hummers modified method.4、Fe3O4/GO composites were synthesized bycoprecipitation method. With the increase of the ratio Fe2+ and Fe3+, the saturation magnetization and the heating rate increased firstly and then decreased. When Fe and Fe3+ ratio is 4:1, magnetic saturation intensity is the highest, and heating rate is the fastest. The with the proportion of Fe3O4 particles in the compound is higher, the greater the hyperthermia temperature.5、The Fe3O4/GO particles suspension were prepared. When the reaction temperature is 80℃, the heating rate of suspension is the fastest, the highest temperature was 81℃.6、Hollow graphene spheres were prepared through self-assembly method firstly, then Fe3O4/HGs composite were prepared. When the concentration of FeCl3 is low, reduction of graphene oxide spheres can effectively prevent agglomeration of Fe3O4; but with the increasing of concentration of FeCl3 solution, reduction graphene oxide spheres can not effectively prevent the aggregation of Fe3O4 nanoparticles. When the concentrationof FeCl3 is 0.05mol/L, the prepared Fe3O4/HGs the first charge/discharge and electrochemical stability are the best.7、Fe3O4/RG were prepared by reduce graphene oxide and different concentration of FeCl3 solution. Electrochemical capacity of Fe3O4/RG increased first and then decreased. When the FeCl3 concentration is 0.05mol/L, cycle stability of Fe3O4/RG and cycle performance are the best.