Diameter control of vertically aligned carbon nanotubes using CoFe2O4 nanoparticle Langmuir-Blodgett films

• Published in: Japanese Journal of Applied Physics Vol. 57; no. 3S2
• Main Authors: Tamiya, Shuhei, Sato, Taiga, Kushida, Masahito
• Format: Journal Article
• Language: English
• Published: The Japan Society of Applied Physics 01.03.2018
• ISSN: 0021-4922; 1347-4065
• DOI: 10.7567/JJAP.57.03EG15

Vertically aligned carbon nanotubes (VA-CNTs) are suggested for utilization as a new catalyst support of polymer electrolyte fuel cells (PEFCs). The independent control of the diameter and number density of VA-CNTs is essential for application in PEFCs. As the catalyst for VA-CNT growth, we fabricated CoFe2O4 nanoparticle (NP) films using the Langmuir-Blodgett (LB) technique. Using the LB technique, we were able to separately control the diameter and number density of VA-CNTs. The number density of VA-CNTs was changed by mixing with the filler moleculer, palmitic acid (C16). The VA-CNT diameter was changed by the adjusting the CoFe2O4 NP diameter. However, the heat-induced aggregation of CoFe2O4 NPs occurred in thermal chemical vapor deposition to synthesize VA-CNTs. Therefore, we examined how to minimize the effect of heat-induced aggregation of CoFe2O4 NPs. As a result, selection of the appropriate number density and diameter of CoFe2O4 NPs was found to be important for the control of VA-CNT diameter.