| With the rapid development of electronic information technology in recent years,mobile phones,computers and other electronic devices have been widely used by people.The problem of electromagnetic wave pollution has become a major problem that is a threat to human health.On the other hand,due to the speedy development of science and technology and the rapid growing of the global population,energy depletion has become a serious problem that all mankind has to face.Therefore,the development and utilization of electromagnetic wave absorbing materials and environmentally friendly energy storage materials have become urgent research projects.As a typical spinel type ferrite,CoFe2O4 has been investigated because of its high curie temperature,strong saturation magnetization,large magnetostriction coefficient,good chemical and physical stability,corrosion resistance and wear resistance.It's widely used in various fields,such as:electromagnetic wave absorption field,lithium ion battery electrode material field,super capacitor electrode material field,low loss magnetic core material field,magnetic static wave device field,etc.In this paper,MoS2/CoFe2O4 composite,Fe3O4/CoFe2O4 composite and rGO/CoFe2O4 nanorods composite were prepared by using molten salt method,hydrothermal method and a simple one-step etching method.And through a series of tests,the microstructure,internal structure,electromagnetic wave absorption performance and electrochemical performance of the above composite materials were analyzed and studied.The research content is divided into four parts.The specific research content is as follows:(1)Preparation and electromagnetic wave absorption properties of MoS2/CoFe2O4 compositesUsing the bulk CoFe2O4 powder prepared by the molten salt method as a precursor,a MoS2/CoFe2O4 composite was successfully prepared by hydrothermal method.The phase and microstructure tests show that the phase of the obtained MoS2/CoFe2O4 composite will not change with the different amount of CoFe2O4 added.In terms of specific surface area,the change of the morphology of the composite material compared to CoFe2O4 makes the specific surface area of the composite material increase.The as-synthesized composites exhibit significantly enhanced microwave absorption properties.And the maximum reflection loss of-59.9 dB was achieved at 11 GHz for the thickness of 2.7 mm in the frequency range of 2?18 GHz.(2)Preparation and electromagnetic wave absorption properties of Fe3O4/CoFe2O4 compositesUsing bulk CoFe2O4 powder prepared by molten salt method and Fe3O4 microspheres prepared by hydrothermal method as precursors,Fe3O4/CoFe2O4 composite was prepared by a simple etching process.The microwav absorption test results show that Fe3O4/CoFe2O4 composites are enhanced in the frequency range of 2?18 GHz.When the matching thickness is 11 mm,the frequency of the absorption peak is 16.9 GHz,the reflection loss of Fe3O4/CoFe2O4 composite reaches the maximum,and the maximum reflection loss is-24.3 dB.(3)Preparation and electromagnetic wave absorption properties of rGO/CoFe2O4 nanorods compositesUsing GO prepared by the improved Hummers method and bulk CoFe2O4 powder prepared by the molten salt method as precursors,rGO/CoFe2O4 nanorods composite was prepared by a one-step etching method.And their micro-morphology,structural composition and microwave absorption properties were characterized and studied.The microwave absorption test results show that the prepared rGO/CoFe2O4 nanorods composite exhibits excellent microwave absorption properties compared with pure CoFe2O4 powder and CoFe2O4 nanorods.And the maximum reflection loss of-56.4 dB was achieved at 16.9 GHz for the thickness of 1.4 mm in the frequency range of 2?18 GHz.(4)Preparation and electrochemical properties of rGO/CoFe2O4 nanorods compositesUsing GO prepared by the improved Hummers method and bulk CoFe2O4 powder prepared by the molten salt method as precursors,rGO/CoFe2O4 nanorods composite was prepared by a one-step etching method.And their micro-morphology,structural composition and electrochemical properties were characterized and studied.The results show that when the amount of rGO added is 60 mg,the specific capacity of rGO/CoFe2O4 nanorods composite is 346.1 F·g-1 at a current density of 1 A·g-1.Compared with pure CoFe2O4,the electrochemical performance has been significantly improved,which shows that it has better electrochemical performance. |
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