Property control of new forms of carbon materials by fluorination

• Published in: Journal of fluorine chemistry 2002-04, Vol.114 (2), p.181-188
• Main Authors: Touhara, Hidekazu, Inahara, Junichi, Mizuno, Tomotaka, Yokoyama, Yu, Okanao, Satoru, Yanagiuch, Katsuaki, Mukopadhyay, Indrajit, Kawasaki, Shinji, Okino, Fujio, Shirai, Hirofusa, Xu, W.H., Kyotani, T., Tomita, A.
• Format: Article
• Language: English
• Subjects: Adsorption; Electrochemical fluorine doping; Fluorination by elemental fluorine; Fullerene C 60; Lithium cells; Multiwall carbon nanotubes
• ISSN: 0022-1139; 1873-3328
• DOI: 10.1016/S0022-1139(02)00026-X

Inner surface fluorinated multiwall carbon nanotubes were prepared by direct fluorination. This selective fluorination results in functionalization and modification of pristine tubes with respect to adsorption and electrochemical properties. Electrochemical oxidation of C 60 thin films yielded C 60F ca.1–3, where fluorine exists as a semi-ionic species in the cavity surrounded by C 60 molecules without forming covalent CF bonds. Multiwall carbon nanotubes (MWNTs) based on the template carbonization technique were fluorinated in a temperature range 323–473 K by elemental fluorine. The fluorination of the carbon nanotubes results in functionalization and modification of pristine nanotubes with respect to adsorption and electrochemical properties. Selective fluorination of the inner surface of the carbon nanotubes, brings about a decrease in the surface free energy of the inner surface of the tubes and an increase in colombic efficiency of Li/nanotubes rechargeable cells in an aprotic medium. Electrochemical fluoride-ion doping of fullerene C 60 thin films (250–450 nm) was carried out in a fluoride-ion conductive solution, MeCN solution of 1 M Et 4NF·4HF. Galvanostatic oxidation yielded C 60F ca.1–3 where fluorine exists as a semi-ionic species in the cavity surrounded by C 60 molecules without forming covalent CF bonds