Nano Metal / Carbon Composites And Characterization

Nano-metal/carbon composite is a new functional material, The role of the carbon coating in this material is to isolate the particles from each other, thus avoiding the drawbacks caused by interactions between closely compacted units, such as the oxidation of the bare nano metal particles. Moreover, the carbon coating can endow these particles with other properties, and then the material is able to be widely used as electroni, electric and electro magneticshield materials, oxidation/reducion catalysts, antibacterial materials and special active carbon etc. presently, most researches focused on the synthesis of nano-metal/carbon from organometallic polymers and macromolecular-metal complexes, which led to some problems, such as high cost, complicated process and difficulty of metal content control. In this thesis, a novel method for the preparation of nano-metal/carbon composite material was proposed, in which D113 resin,carbon black,activated carbon,was used as carbon source and metal salt as metal source in order to prepare nano-metal and alloy/carbon composite particles, via pyrolysis in the range of 500-1300℃.The structural morphologies of the nano-metal/carbon composite particles are investigated by XRD, IR, TEM etc and the effects of preparation conditions on morphologies of nano-metal/carbon composite particles are studied.The result showed that PbO₂ and Ni were observed in Pb/C and Ni/C which were prepared from carbon black and activated carbon precursors respeitively.Carbon-encapsulated Ni nano-particles are prepared by pyrolysis of Ni/D113 precursors from 400℃to 700℃. It reveales that the nickel particles existe mainly in the form of fcc Ni phase, and no evidence of Ni oxides or carbides are observed, and it is found that the particles sizes of Ni increase with the increasing of pyrolytic temperature. But when Fe/D113 precursor is pyrolysed in the range of 400-700℃, the crystal structure of the iron particle is different. The products are mainly iron oxides andα-Fe as Fe/D113 precursor pyrolysed at 500℃, and as the pyrolytic temperature increases to the range of 600-700℃,α-Fe and Fe₃C are observed. Meanwhile, Al₂O₃,MgO,MgAl₂O₄ were observed in Al/C, Mg/C, Al-Mg/C which were prepared from D113 resin at 1000-1300℃.