Synthesis And Properties Of Carbon Nanocomposites

Carbon nanotubes (CNTs) and graphene, the sp2hybrid carbon structure of the carbon nanomaterials, have been intensively investigated in the fields of physics and materials due to their unique structures and excellent properties. Transition metal nanoparticles and metal sulfide nanoparticles have also been used in various fields due to their excellent properties. The composite materials based on carbon nanotubes and graphene have developed into a very important direction. In this paper, we have synthesiaed Fe/CNTs nanocomposites and Ni/graphene nanocomposites by chemical vapor deposition, and prepared FeS2/graphene and Fe7S8/graphene nanocomposites by solvothermal method, successfully. The main contents are as fllows:(1) Fe-Fe3C-Fe4C0.63/CNTs have been in-situ synthesized by chemical vapor deposition process using phenol and ferrocene as raw materials. XRD, SEM and TEM were used to characterize the structure and morphology of the product. The impacts of the reaction temperature, Ar gas flow rate and the ratio of raw material on the product were investigated. The results demonstrate that the best synthesis temperature is1000℃and the appropriate Ar gas flow is around70～150sccm, and the best mole ratio for phenol and ferroncene is4:1when the H2gas flow is50sccm. We can prepare filled carbon nanotubes array at the above conditions(2) Ni/graphene nanocomposites have been in-situ synthesised by chemical vapor deposition process using nickel-dimethylglyoxime as raw materials successfully. XRD, SEM and TEM were used to characterize the crystal structure and morphology, the appropriate reaction temperature is700℃. The growth mechanism, magnetic properties, microwave absorbing and electrochemical properties of Ni/graphene nanocomposites have been studied. The results demonstrate that graphene-Ni nanocomposites exhibit improved magnetism and saturation magnetization. The electromagnetic of the product were studied, the absorbing peaks shift towards lower frequency with increasing hickness, but the maximum absorbing values of the graphene composite are all around-13dB but with different frequency region. Ni/graphene nanocomposites exhibit excellent electrochemical ethanol sensing properties:there is good response to5ppm ethanol in NaOH aqueous solution.(3) FeS2/graphene and Fe7S8/graphene nanocomposites have been synthesized by a simple efficient, and one-step solvothermal process using ferrocene and sulfur powder as raw materials, ethanol, o-dichlorobenzene and hexane as solvent. SEM, XRD and TEM were used to characterize the crystal structure and morphology. The results demonstrate that when the ferrocene and sulfur powder mole ratio is1:2, the product is FeS2/graphene nanocomposites; when the ferrocene and sulfur powder mole ratio is1:2.5, the product is Fe7S8/graphene nanocomposites. The sample is flowerlike when the ethanol is used as solvent, and it is balllike when o-dichlorobenzene or hexane is used as solvent.