Multi-walled Carbon Nanotubes Synthesis by Arc Discharge Method in a Glass Chamber

Abstract. In the present paper, carbon nanotubes (CNTs) were synthesized by arc discharge method by vaporizing graphite rods in the presence of Ni and a Ni/Y mixture as catalysts for subsequent use in electrical energy storage and conversion devices. CNTs synthesis was carried out in a cylindrical glass reactor applying a controlled Argon flow of 1.43 cm3/min and a chamber pressure of 39 kPa. Carbon powder was collected from the reactor following chemical treatment with HCl solution at 1 M to remove the metallic impurities. Morphology obtained by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed multi-walled nanotubes (MWCNTs) with amorphous carbon particles attached to their surface. Fourier transform infrared (FT-IR) spectra presented bands at 1550 and 1200 cm–1 corresponding to the C=C bond characteristic to the CNTs skeleton; these bands were not present in pristine graphite. Electromagnetic absorbance was observed using ultraviolet-visible spectroscopy (UV-Vis) showing peaks at 204 and 256 nm related to sp2 hybridization characteristic for MWCNTs.   Resumen. En el presente trabajo se sintetizaron nanotubos de carbono (NTCs) por el metodo de descarga de arco mediante la vaporizacion de barras de grafito en presencia de Ni y una mezcla de Ni/Y como catalizadores para su posterior uso en dispositivos de almacenamiento y conversion de energia electrica. La sintesis de NTCs se realizo en un reactor cilindrico de vidrio aplicando un flujo controlado de Argon de 1.43 cm3/min y una presion de camara de 39 kPa. El polvo de carbon se recolecto del reactor y se trato quimicamente con una solucion de HCl a 1 M para eliminar las impurezas metalicas. La morfologia obtenida por microscopia electronica de barrido (MEB) y microscopia electronica de transmision (MET) mostro nanotubos de paredes multiples (NTCPMs) con particulas de carbon amorfo adheridas a su superficie. Los espectros de infrarrojo transformada de Fourier (FT-IR) mostraron bandas en 1550 y 1200 cm–1 que corresponden al enlace C=C caracteristico de los NTCs; estas bandas no estuvieron presentes en el grafito pristino. La absorbancia electromagnetica se observo mediante espectroscopia ultravioleta-visible (UV-Vis) mostrando picos a 204 y 256 nm relacionadas con la hibridacion sp2 caracteristica de los NTCPMs.