Synthesis of Single-Walled Carbon Nanotube Film on Quartz Substrate from Carbon Monoxide

1. INTRODUCTION The discovery of single-walled carbon nanotubes (SWNTs) in 1993 by Iijima and Ichihashi [1] has stimulated many researchers to utilize for the innovative technology, especially applications to electronic or optic devices in which SWNTs are used as grown on substrates. However, the technical development for decreasing impurities and defects, controlling physical properties, shapes and sizes, and economical mass-synthesis is necessary for utilizing the unique physical properties of SWNTs [2]. Bulk production techniques of SWNTs were developed as HiPco [3] (decomposing high-pressure CO with floated Fe particles), ACCVD [4] (decomposing alcohol with Co/Fe supported on zeolite), and CoMoCAT [5] (decomposing CO with Mo/Co supported on silica particles). On the other hand, direct synthesis of high-purity SWNTs on silicon and quartz substrates using catalytic chemical vapor deposition (CCVD) technique from alcohol was demonstrated [6]. Later, by the efficient CVD reaction, vertically aligned SWNTs film was also achieved [7]. Recently, Hata et al. [8] demonstrated much more efficient and longer growth of SWNTs on a Si substrate from ethylene. However, physical properties are not fully controlled by these methods. Electric Power Development Co.,Ltd. (J-Power) is studying on utilizing carbon monoxide gas to the carbon source of carbon nanomaterials such as SWNTs, graphite nanofibers (GNFs), etc. Carbon monoxide gas is produced in numerous industrial plants. Furthermore, carbon dioxide gas is exhausted from most industrial plants as one of Greenhouse gases, and it can be converted to carbon monoxide gas using Bosh reaction [9]. In the present report, SWNTs were synthesized directly on a substrate using a liquid-based approach for the catalytic mount, in combination with the carbon monoxide CCVD method. We here report characteristics of synthesized SWNTs using above method.