Preparation Of Several Fe₃O₄ Nanocomposite Materials With Magnetic Performance

At present,most of the preparation methods for magnetic Fe₃O₄?FeO·Fe₂O₃?materials are different because of diverse sources of iron.Briefly,alkaline precipitating agent and reductant are needed to make the appropriate amount of Fe³⁺convert into Fe²⁺when used Fe³⁺salt as iron source.Simultaneously,if the Fe²⁺salt is used as the iron source,the amount of Fe²⁺(easily oxidized to Fe³⁺)into Fe³⁺needs to be controlled besides alkaline precipitant.In addition,it is also necessary to control the experimental conditions strictly in addition to adding alkaline precipitant when used the stoichiometric ratio of Fe²⁺,Fe³⁺salt as iron source.In any case,many disadvantages,including complex preparation condition,harsh reaction control,high costs,and environmental pollution,significantly hinder the preparation of Fe₃O₄ with high purity and excellent performance.In view of the above problems,we carried on novel hydrothermal and solvothermal methods to prepare serious of Fe₃O₄nanocomposites.During the synthesis process,only single iron source(such as Fe²⁺/Fe³⁺salt),polymer monomer are used except for any other additives,such as alkaline reagents,oxidation/reducing agent,catalyst,surface modifier,etc.,and thus,a series of Fe₃O₄ nanocomposite materials?Fe₃O₄/C,PANI/Fe₃O₄,PANI/Fe₃O₄/C,PS/Fe₃O₄/C?were prepared via one-step green synthesis,which has the advantages of low cost,short process,high effect,simple operation,green environmental protection and other prominent advantages.detailed research and results are as follows:1.One-step green preparation of Fe₃O₄/C and PANI/Fe₃O₄ magnetic nanomaterials by using Fe³⁺?Fe?NO₃?₃·9H₂O?as iron source.?1?Fe₃O₄/C magnetic nanocomposites were prepared by using Fe³⁺salt?Fe?NO₃?₃·9H₂O?as iron source,chicken feather-CF as carbon source and reducing agent and ethanol as solvent.The effects of solvothermal temperature,time,solvent and the amount of CF on the formation of Fe₃O₄ and magnetic properties were investigated in detail.The typical results were drawn through XRD,IR,XPS,TEM,SEM,and VSM analysis In this experiment,the transformation amount of Fe³⁺into Fe²⁺(Fe³⁺?Fe²⁺)could be ensured by regulating the amount of CF without any other reagents?such as precipitation agent and reducing agent?,which guarantees the convert of Fe³⁺into Fe₃O₄(Fe³⁺?Fe₃O₄)and thus the Fe₃O₄/C magnetic nanocomposite materials with good magnetic properties.?2?PANI/Fe₃O₄magnetic nanocomposites were prepared via one-step solvothermal method by taking?Fe?NO₃?₃·9H₂O?as an iron source,aniline?AN?as a monomer and reducing agent.The effects of solvothermal temperature,solvent,the amount of AN on the formation of target Fe₃O₄,and the electric-magnetic performance of the product were studied,respectively.The typical results were drawn through XRD,IR,XPS,TEM,SEM,and VSM analysis In this experiment,the transformation amount of Fe³⁺into Fe²⁺(Fe³⁺?Fe²⁺)could be ensured by regulating the amount of An without any other reagents?such as precipitation agent and reducing agent?,which guarantees the convert of Fe³⁺into Fe₃O₄(Fe³⁺?Fe₃O₄)and thus the Fe₃O₄/C magnetic nanocomposite materials with good magnetic properties.2.One-step green preparation of Fe₃O₄/C,PANI/Fe₃O₄/C and PS/Fe₃O₄/C magneticnanocompositesbyusingFe²⁺?ferrousgluconate-Fe?OOC?CH₂OH?₄CHOH?₂·2H₂O?as the source of iron and carbon.?1?Fe₃O₄/C nanocomposite with graphene like structure were prepared via one-step green hydrothermal method by using Fe?OOC?CHOH?₄CH₂OH?₂·2H₂O as iron source and carbon source,water as solvent.The materials were characterized by XRD,IR,XPS,TEM,SEM,VSM,and the corresponding results show the successful preparation of Fe₃O₄/C magnetic nanomaterials with strong interaction by one-step hydrothermal method.During the preparation process,no additional alkaline precipitation agent,oxidant,catalyst,and surface modification of Fe₃O₄ materials were carried.Furthermore,in the hydrothermal process,the redox reaction of Fe²⁺?Fe³⁺?the oxidation reaction?occurs in the Fe(OOC?CHOH?₄CH₂OH₂·2H₂O molecule:Fe²⁺?Fe³⁺Fe²⁺:intramolecular oxidation reaction(Fe³⁺)to ensure that the conversion of Fe²⁺+Fe³⁺?Fe₃O₄,CH₂OH?CHOH?₄COO^2-?C?reduction?,namely that the CH₂OH?CHOH?₄COO^2-made the partial of Fe²⁺oxidant into Fe³⁺,further converted into Fe₃O₄,as well as the carbon source.In the presence of Fe²⁺,the material was transformed into a high degree of carbon material by hydrothermal process,thus achieving a single raw material Fe?OOC?CHOH?₄CH₂OH?₂·2H₂O prepared target materials Fe₃O₄/C by one step.That is:Fe²⁺+CH₂OH?CHOH?₄COO^- Hydrothermal process Fe₃O₄+C?2?In the absence of catalyst,precipitating agent,oxidizing agent,a series of magnetic nanocomposite materials with PANI/Fe₃O₄/C,PS/Fe₃O₄/C which were different from polyaniline?PANI?,polystyrene?PS?were prepared by hydrothermal method with Fe?OOC?CHOH?₄CH₂OH?₂·2H₂O as raw material,aniline?AN?and styrene?S?as organic monomer,respectively.