Synthesis of Boron-Doped Carbon Nanotubes With DC Electric Arc Discharge

Boron-doped carbon nanotubes (B-doped NTs) are predicted to behave as semiconductors over a large range of diameters and chiralities and might thus constitute a suitable class of materials for nanoelectronics technology; they could be used, for example, to enhance properties of supercapacitors as capacitance and time of charge/discharge. In this paper, we propose an electric arc to synthesize B-doped NTs, based on the erosion of graphite electrodes with nickel and yttrium as catalysts and boron as the doping element. This technique allows obtaining carbon nanotubes (NTs) doped with around 8% of boron, in a short amount of time (2 min) and under relatively low applied power (2 kW). B-doped NTs were characterized with scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. Physical properties of the plasma were also studied using optical emission spectroscopy. Temperatures of around 5000 K were obtained suggesting a high concentration of C
₂
molecules and then, the ideal conditions to synthesize NTs.