Synthesis of Carbon Nanohelices Using Sn Based Bi-Metal Oxide Catalysts

In this article, we report the synthesis of carbon nanohelices (CNH) by catalytic chemical vapor deposition (CCVD) technique using novel inorganic bi-metal oxide catalysts. The catalysts chosen have the general form X-Sn-O, where X refers to element having high carbon solubility such as Fe and Ni. These catalysts are synthesized by simple sol-gel technique. The CNH are grown by CCVD method at a temperature of 700 °C by taking acetylene as the carbon source. A reasonably good yield (40-60%) of CNH is obtained with each catalyst. The catalysts and CNH are characterized using different experimental techniques like X-ray diffraction, Raman spectroscopy, electron microscopy and thermogravimetric analysis. These characterizations suggest that morphology as well as the constituents of the metal oxide catalysts have significant influence on the coil and spiral growth of CNH. Finally, electrochemical study of the CNH shows good catalytic activity in 1 M H2SO4 aqueous solution compared to bare electrode and is therefore ideal for many applications.