| Nanocarbon materials including fullerenes, carbon nanotubes and graphene, have become the hot topics in recent years and play a leading role in the nanoscience and nanotechnology. Many breakthroughs have been accomplished both in the synthesis technique and theoretical research. However, the insolubilities of controllable fabrication in large-scale and growth mechanism still act as the main bottle-necks and limitations to their application widely in industry world. This work in the dissertation used various starting materials with different structures and compositions and investigated the controllable preparation, separation and purification of fullerene and carbon nanotubes based materials, meanwhile the mechanisms of hydrogenation and halogenation of the fullerenes with less carbon atoms than 60 have been studied theoretically.The main results are summarized as following:(1) By means of optimizing the operating conditions, the compositions and structures of the solid carbon starting materials, high yields of fullerene have been achieved in the process of arc discharge. Silicon-controlled rectifier with twelve-pulses has been used to minimize the fluctuation of direct-current (DC) wave for the stabilization of the arc discharge. Higher yield of fullerenes has been accomplished compared with that in the case of six-pulses. Anthracite, needle-coke, exfoliated graphite as well as graphite can be used as the starting materials for the production of fullerenes in the arc discharge, and the exfoliated graphite give rise to the highest yield of fullerene. Therefore, this suggests that there is an inherent relationship between the yield of fullerenes and structures of carbon precursors.(2) High purity of fullerene has been achieved by means of simulated moving bed (SMB) chromatography technology from the raw fullerenes obtained by arc discharge. Ball-like ODS with diameter of 20-30μm and pore size of 12nm is used as the stationary phase and the mixture of methanol and toluene as the eluent for the separation of fullerene. High purity (98% for both C60 and C70) and high extraction yield (95.7%,98% for C60 and C70, respectively) have been obtained. This demonstrates that the SMB chromatography technology is a high efficient approach to the purification of fullerenes.(3) Coal and needle-coke are used as the carbon source for the production of carbon nano-materials with various morphologies. With Baiyangshu coal (anthracite) as starting materials and He (0.020MPa) as discharge atmosphere, bamboo-like carbon nanotubes with diameter of 20-30nm and open end, as well as fluffy ball-like assemblies composed of carbon nanofibers with diameter of 20-30nm are grown in large-scale. Needle-coke with high optical anisotropy is used as carbon source and iron powder as catalyst, nanorods decorated with Fe nanoparticles (5-10 nm) on the surface and length of micrometer size are obtained with arc discharge method; While double-walled carbon nanotubes with high yield and high quality rather than Fe decorated nanorods are prepared with FeCl3 replacing of Fe powder as the catalyst precursor. This indicates that the needle-coke is the appropriate precursor for the production of double-walled carbon nanotubes.(4) Density functional theory is used to predict the fullerenes interacted with H, F and Cl atom for the purpose of pursuing valuable information for the growth mechanism of nanocarbon materials. Through the analysis of the potential energy surface and calculation of activation energy for the conversion between different isomers, the hydrogenation and halogenation mechanism of C2s(Td), C40(Td) are predicted with this theory. It demonstrates that the reaction between C28(Td), C4o(Td) and X(X=H,F,Cl) is easy and give rise to stable compounds of C2s(Td)X4 and C4o(Td)X4, respectively. It is shown that the conversion between isomers of C28(Td)X, C40(Td)X is a one step reaction, which become impossible at the room temperature because of the high energy barrier in the reaction channel.
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