Synthesis of carbon nanofibers and nanotubes by chemical vapor deposition using a calcium carbonate catalyst

Carbon nanofibers (CNFs) and nanotubes (CNTs) were successfully synthesized by chemical vapor deposition using a novel catalyst CaCO3. The reaction process of C2H2 on CaCO3 surface could be classified into three stages; stage I: dehydrogenation reaction (88–129 °C), stage II: dehydrogenation and hydrogenation reactions (129–686 °C) and stage III: dehydrogenation reactions (higher than 686 °C). It was found that the molecular weights of the crosslinked C2H2 products increase with the increase of reaction temperature. Nevertheless, the dehydrogenation reaction of C2H2 into CNFs took place only at a temperature higher than about 500 °C and the highest yield of CNFs occurred at about 600 °C.

► For the first time, the carbon nanofibers were synthesized by chemical vapor deposition using a calcium carbonate catalyst.
► It was found that calcium carbonate is very active for decomposing C2H2.
► The catalytic activity of calcium carbonate on decomposing C2H2 was studied in detail.
► The deposition behaviors of carbon nanofibers at various temperatures were systematically explained.