Effect of cupped cathode on microstructures of carbon nanotubes in arc discharge

The preparation of carbon nanotubes by dc arc discharge using a carbon cathode coated with catalyst

“…In this case, the variation of the inner diameter of the MWNTs was less than 4 nm, whereas the variation range of the outer diameter reached more than 10 nm under the same conditions. Moreover, Tang reported that when a flat cathode was used the distribution of the inner diameter was smaller than that of the outer diameter [20]. On account of these results, we expect the forming mechanisms of the inner and outer walls of the CNTs to differ.…”

“…We think that the density of the carbon species might be responsible for the thickness of the CNT diameter and that the temperature gradient in the arc area might be responsible for the distribution of the CNT diameter [20]. A higher density carbon supply yields greater growth of the CNT walls.…”

Carbon Nanotube and Its Derived Nanomaterials Based High Performance Biosensing Platform

“…In the arc discharge method, CNTs get synthesized by sublimation of a carbon precursor. Carbon black [ 43 , 44 , 45 , 46 ] and graphite [ 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ] are commonly used in this scenario although some other carbon precursors namely fullerene waste soot [ 57 ], polyvinylalcohol [ 58 ], and other hydrocarbons including toluene, xylene, cyclohexane, cyclohexanone, n-hexane, n-heptane, n-octane, and n-pentane [ 59 ] are also reported. Some important parameters namely, the pressure of the inert gas, optimal voltage as well as the choice of the catalysts are critical for synthesizing highly pure CNTs via this method.…”