Synthesis of carbon nanotubes by microwave heating: Influence of diameter of catalytic Ni nanoparticles on diameter of CNTs

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 2; no. 8; pp. 2773 - 2780
• Main Authors: Ohta, Kazuchika, Nishizawa, Toshiki, Nishiguchi, Takahiro, Shimizu, Ryo, Hattori, Yoshiyuki, Inoue, Shuji, Katayama, Masakazu, Mizu-uchi, Kazuhiko, Kono, Takumi
• Format: Journal Article
• Language: English
• Published: 01.01.2014
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c3ta13297h

We rapidly synthesized multi walled carbon nanotubes (MWCNTs) by calcination of granulated polystyrene with nickel nanoparticles having different average diameter (D sub(Ni) = 10, 20, 50 or 90 nm) under nitrogen gas at a certain temperature and time (700 degree C, 15 min or 800 degree C, 10 min), using a domestic microwave oven in order to systematically investigate the influence of the diameter of nickel nanoparticles on the diameter of MWCNTs. The MWCNTs synthesized here were characterized by a transmission electron microscope, a Raman spectrophotometer and a wide angle X-ray diffractometer. We found that for the calcination condition of (800 degree C, 10 min), a relationship between the outer diameter of the resulted carbon nanotubes (D sub(CNT)) and the diameter of catalytic nickel nanoparticles (D sub(Ni)) can be described as a linear function, D sub(CNT) = 1.01D sub(Ni) + 14.79 nm with the correlation coefficient R= 0.99, and that for the calcination condition of 700 degree C, 15 min, D sub(CNT) = 1.12D sub(Ni) + 7.80 nm with R= 0.95. Thus, we revealed that when the diameter of the catalytic nickel nanoparticles (D sub(Ni)) increases by 1 nm, the outer diameter of the obtained MWCNTs (D sub(CNT)) increases by about 1 nm.