Hydrogen Adsorption Properties of Commercial and As-Synthesized CNTs

• Main Authors: Yu-Shan Chang, 張宇杉
• Other Authors: Hong-Wen Wang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/57886680185300181838

碩士 === 中原大學 === 奈米科技碩士學位學程 === 98 === In this study, multiwall carbon nanotubes were synthesized using low pressure chemical vapor deposition (LPCVD). The growth of carbon nanotubes on Si wafer substrates was explored by using varied amount of ferric nitrate solutions and different particle sized Al2O3 (1μm, 0.3μm, 0.1μm) powders as the catalytic agents. Commercial carbon nanotubes (NCT tubes, Japan) as well as the as-synthesized carbon nanotubes were examined for their capability in hydrogen storage. The specification of commercial CNT was more than 99.5% of multi-walled carbon nanotube (MWCNT), 50-100 nm in diameter, and > 10 mm in length. Additives such as Pt nanoparticles, and Au nanoparticles, and dopants such as K were introduced to the studied carbon nanotubes in order to investigate their influences on hydrogen adsorption. The adsorption of hydrogen for the commercial carbon nanotubes (C-CNTs) was 0.0876 wt%. For Pt/CNTs, the H2 adsorption was 0.0225 wt%, the Au/CNTs 0.0604 wt%, and the K-CNTs 0.0908 wt%. The potassium ion-doped CNTs exhibited better hydrogen storage efficiency than others cases in this study. Hydrogen adsorption for as-synthesized carbon nanotubes (S-CNTs) is 0.0885 wt%, and the dopant of potassium ions could enhance the value up to 0.1199 wt% (SK-CNTs.) It was also confirmed that the higher defects in as-synthesized CNTs than those of commercial CNTs was the reason of their higher H2 adsorption capability. Raman spectroscopy, SEM, XRD, and TEM were employed to characterize all CNT materials in this study.