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A massive growth of vertically-aligned single-walled carbon nanotubes (VA-SWCNTs) from aluminum oxide (Al-O)-supported Co catalyst and high purity ethanol was performed using alcohol catalytic chemical vapor deposition (ACCVD) technique. SWCNTs with 50-μm thickness were grown on the substrates via this technique. The Al metal layer of 20 nm thickness was thermally-oxidized for the production of Al-O, and 0.5 nm cobalt (Co) thin films was used as catalyst for the CVD process. The CNT growth was optimized using SiO2/Si substrates, and similar experimental condition was applied to the conducting substrates. The as-grown CNTs were characterized using Raman spectroscopy and electron microscopies for growth confirmation and for quality level investigation. Development of the catalyst nanoparticles and Al-O support layer was observed using atomic force microscopy (AFM) and transmission electron microscopy (TEM). The electrodes were fabricated using directly-grown VA-SWCNTs on SUS 310S, and were successfully used as an electrochemical capacitor. Electrochemical analysis using KOH aqueous electrolyte was performed by cyclic voltammetric (CV) and galvanostatic chargedischarge measurements; a maximum 52 Fg-1specific gravimetric capacitance was obtained from the VA-SWCNT electrodes.
vertically-aligned SWCNTs, ACCVD, direct growth method, conducting substrates, electrochemical capacitor
This work was supported by a Grant-in-Aid from Japan Society for the Promotion of Science (JSPS) for Research Fellows. Part of this work was supported by Ministry of Education, Culture, Sports,
Science and Technology, Japan (MEXT), Ministry of Higher Education Malaysia (MOHE) and Universiti Teknikal Malaysia Melaka (UTeM). Authors acknowledge Dr. Hiroshi Uemachi (Polythione
Inc.) for sharing his expertise in electrochemistry. We are also grateful to Ms. Mary Ann Mooradian for the proof-reading and English correction of the manuscript.
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