Catalysts effects on the production of carbon nanotubes by an automatic arc discharge set up in solution

Abstract

Carbon nanotubes (CNTs) represent an important group of nanomaterials with attractive geometrical, electrical and chemical properties and are synthesized using a variety of techniques. CNTs have been extensively studied in our previous works and in this study were fabricated by arc discharge full automatic set up in liquid which does not require vacuum equipment, heat exchange system, active or inert gases. This technique was full automatic which enabled the controlling of gap between the two electrodes. The effect of the kind of catalyst on quantity of synthesized CNTs was studied herein. Carbon nanotubes were fabricated between two graphite electrodes which were submerged in the LiCl 0.25N as a solution and with a voltage of 25v. For comparative studies, Ni, Mo, Fe and Ni‐Mo were exploited as metallic or bimetallic catalysts and the results were subsequently analyzed, compared and discussed. In order to analyze the morphology of the synthesized products a scanning electron microscopy (SEM) as well as transmission electron microscopy (TEM) study were employed. Based on Mo‐Ni as catalysts in carbon electrode, high‐crystalline and alonged multi walled carbon nanotubes (MWCNTs), single walled carbon nanotubes (SWCNTs) and spring‐like carbon nanotubes (SCNTs) were synthesized by using this unique technique. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Influence of the solution temperature on carbon nanotube formation by arc discharge method

“…A TEM characterisation of this sample shows that the diameter of the CNTs is about 2-5 nm and their length in micrometres. Therefore, this sample is good enough and its result is acceptable in comparison to the results of reported studies [11,12]. Constant temperature around 25 C is the best thermal condition for synthesising CNTs by the arc discharge method in liquid.…”

“…Catalysts which were used to prepare CNTs usually include transition metals. In this study, Ni and Mo are used as the mixture of two catalysts [12]. Conditions of voltage, type of solution and type of catalyst were optimised in our previous works.…”

“…Lange et al [8] generated onions, nanotubes and encapsulates by arc discharge in water. Recently, arc discharge in liquid has also been developed to synthesise fullerenes [7] and CNTs [9][10][11][12]. These liquid environments include liquid nitrogen [7,13], deionised water [9,10], aqueous solution LiCl, KCl and NaCl [10,11].…”

“…In our previous work, parameters such as voltage [5], current, type of catalyst [12] and type of solution were studied and optimised [11]. In this article, the effect of temperature of solution on the synthesis of CNTs and the structure of fabricated CNTs is studied.…”

Synthesis of carbon nanotubes by arc-discharge and chemical vapor deposition method with analysis of its morphology, dispersion and functionalization characteristics

“…In laser-ablation method a high intensity laser beam is used for the sublimation of graphite and gives high-quality and high purity nanotubes, but the drawback is high cost of synthesis [6][7][8]. Classically carbon nanotubes are synthesized by arc-discharge method, in which an arc is generated in between two graphitic rods kept at a certain distance of few mm [9][10][11][12][13]. This method is cost-efficient.…”