Hydrothermal Synthesis And Properties Research Of Fe-M Oxide Nanohybrids

Hydrothermal method is an approach to crystallize substances from high-temperature?100?1000??aqueous solutions at high vapor pressure?1?100 MPa?in a steel pressure vessel called an autoclave.Hydrothermal method makes it possible to prepare product by recrystallzing indissolvable or undissolvable crystals.Hydrothermal method can be defined as a method of synthesis of desired crystals that depends on the solubility of minerals in hot water under high pressure.Solvothermal method is a method of producing chemical compounds.Solvothermal method is similar to the hydrothermal method,the only difference is that the precursor solution is usually not aqueous solution.Hydrothermal method and Solvothermal method are now widely used in material preparation,chemical reactions and treatments.Nickel ferrite-reduced graphene oxide?Ni Fe₂O₄-r GO?nanohybrids were synthesized via a hydrothermal method successfully.The morphology and phase composition of as-prepared products were analyzed by X-ray diffraction?XRD?and field-emission scanning electron microscopy?FESEM?.The results show that the well-crystalized Ni Fe₂O₄nano octahedrons with edge of 100 nm grew on the surface of r GO successfully.The magnetic property of the synthesized nanohybrids at room temperature was characterized by a vibrating sample magnetometer?VSM?.The result shows that the nanohybrids have high saturation magnetization of 76.8 emug^-1and present a superparamagnetism property.The electrochemical property of the obtained nanohybrids was characterized by a Eight-channel battery tester through using the nanohybrids as the cathode material of a lithium-ion battery.It is found that the obtained nanohybrids have an initial discharge capacity of 1469 m Ah·g^-1and a charge capacity of 652 m Ah·g^-1when the charge-discharge rate is 0.1 C.Coin-like?-Fe₂O₃nanoparticles were synthesized successfully through a solvothermal method in EG/DEG mixed solution with PVP as surfactant and Na OAc as alkali source.The phase composition and morphology of as-prepared products were analyzed and studied.It was found that the EG/DEG ratio in the mixed solution plays a key role in the formation of coin-like?-Fe₂O₃nanoparticles.The magnetic property of the synthesized coin-like?-Fe₂O₃nanoparticles at room temperature was also characterized.The result shows that the coin-like?-Fe₂O₃nanoparticles have a saturation magnetization of 7.678 emug^-1and present a superparamagnetism property.The electrochemical property of the obtained coin-like?-Fe₂O₃nanoparticles was characterized through using the coin-like?-Fe₂O₃nanoparticles as the cathode material of a lithium-ion battery.It is found that the obtained coin-like nanoparticles have an initial discharge capacity of 393 m Ah·g^-1and a charge capacity of 236m Ah·g^-1when the charge-discharge rate is 0.1 C.