Study on the Synthesis of Carbon Nanotubes using the Catalyst Metal Deposited Carbon Cathode Electrode in a DC Arc Disch
- PDF / 1,922,329 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 67 Downloads / 203 Views
0900-O09-09.1
Study on the Synthesis of Carbon Nanotubes using the Catalyst Metal deposited Carbon Cathode Electrode in a DC Arc Discharge Process Hyeon Hwan Kim1 and Hyeong Joon Kim1 1 School of Material Science & Engineering, Seoul National University Seoul, 151-744, Korea ABSTRACT Carbon nanotubes (CNTs) were grown using a dc arc discharge process and relevant process parameters were investigated. Unlike the usual process in which a carbon anode is filled with metal catalyst powder, CNTs were prepared using a carbon cathode on which the metal catalyst had been deposited using an electroplating system. Various transition metals, Ni, Co and Ti, were used as a catalyst. The results show that multi-walled carbon nanotubes (MWNTs) and single-walled carbon nanotubes (SWNTs) can both be synthesized using this technique. And yield and morphology of the prepared CNTs varied depending on the experimental condition and catalyst. While MWNTs were produced in the deposit and soot sample, SWNTs with diameters near 1nm were only detected in the soot collects. When Ni film was used as a catalyst, the yield of SWNTs was higher than in case of using Co or Ti film as a catalyst. From these results, the optimized preparing condition of CNTs and the properties of a good catalyst are discussed.
INTRODUCTION Recently, carbon nanotubes (CNTs) have attracted interest as a new nanomaterial due to their excellent mechanical, electrical, and chemical characteristics [1, 2]. Large scale, high yield and low cost preparation methods of CNTs have become an important research goal. Various methods of CNT synthesis have been developed, but there are many problems associated with these methods [3, 4]. In the ordinary arc process for preparing single-walled carbon nanotubes (SWNTs), transition metal powder is used as a catalyst which is embedded in the carbon anode. These SWNTs have high crystallinity due to the high synthesizing temperature [5]. However, the yield of CNTs is low and an additional purification step is needed. Also, it is unclear when and how the evaporated metal catalyst from the anode reacts with carbon molecules to form CNTs. In the present experiment, the role of the catalyst metal was investigated using a carbon cathode upon which catalyst metal had been deposited. The experimental results have elucidated the role of the catalyst and the reaction mechanism in high-quality mass production of CNTs.
0900-O09-09.2
EXPERIMENT A rod-shaped carbon anode with dimensions of 6mm(Φ) x 80mm(length) and a cube-shaped carbon cathode of 40 mm (length) x 40 mm (height) x 10 mm (thickness) were used for the experiment. Transition metals, Ni, Co and Ti, were used as catalyst and were coated at thickness near 1,000nm. The 0.5 to 2mm gap between the graphite electrodes was controlled manually. Arc plasma was generated at currents from 40 to 100 A under voltages of 18 to 30 V with 500 Torr of He pressure. After arc generation, hard cylindrical deposits in the central area of the carbon cathode and flakes of soot around the cathode and the uppe
Data Loading...
