Study On The Macroscopic Quantity Preparation Of Nano Onion-Like Fullerenes

Study on fullerenes is an frontier interdisciplinary subject which is related to plenty of areas such as physics, chemistry, materials, biology and so on. As a new member of fullerene family, nano onion-like fullerenes have shown some potential and promising applications. Regretfully, the lack in the quantity preparation and effective refinement methods results in the difficulty in the characterization of nano onion-like fullerenes. At present, study on nano onion-like fullerenes is still staying at experimental stage.In this paper, a new method of vacuum heat-treatment was used to prepare macroscopic quantity of nano onion-like fullerenes. By the experiment, the process parameters were investigated that play important roles in the preparation of nano onion-like fullerenes. Firstly, the optimum heat-treatment parameters were evaluated, such as temperature, heating rate and retention time. Secondly, the roles of different catalysts were investigated. It was found that the activity and category of the catalysts play a special role in the preparation of nano onion-like fullerenes. The main conclusions are summarized as follows: The process parameters were given that play an important role in thepreparation of nano onion-like fullerenes. The optimum heat-treatment parameters used in the experiments were that temperature was about1700~2000C,heating rate was about 20~30C/min and retention timeis1h. Different catalysts were used in the experiment. It was found that macroscopic quantity of nano onion-like fullerenes can be prepared by using of the catalyst of Al. When Co, Ni or Al2O3 were used, macroscopic quantity of nano onion-like fullerenes can not be prepared. And when Cu or Si was used, none of the nano onion-like fullerenes were observed. The growth mechanism of nano onion-like fullerenes was discussed. It was suggested that the growth mechanism may be explained by meaning of the liquid-solid model.