Preparation of carbon nanofibers by the floating catalyst method

Carbon nanofibers with diameters of 10 similar to 100 nm were produced by the floating catalyst method, which has a high productivity due to its continuous production and has potential applications in industrial engineering. Several experimental parameters, such as sulfur additives, the evaporating temperature of feedstock (T-bw) and the hydrogen flow amount, have evident effects on the growth of carbon nanofibers. The samples were observed by transmission electron microscopy. It is shown that only an optimal amount of sulfur in feedstock is needed to obtain filamentous carbon. It is also indicated that the T-bw is a key factor for the production of carbon nanofibers. In order to obtain thinner, straighter carbon nanofibers, a low T-bw of 205 similar to 230 degrees C was needed. The amount of hydrogen flow also plays an important role in the floating catalyst method, and the effect of hydrogen is a complex problem. Our experiments showed that a lower hydrogen flow amount is needed to obtain carbon nanofibers with smaller diameters. (C) 2000 Elsevier Science Ltd. All rights reserved.