分别以甲烷-氢气和甲烷-氢气-水的混合气作为反应气源,利用Fe2O3/Al2O3二元气凝胶作为催化剂于900℃反应30min合成了单壁碳纳米管。并采用SEM、XRD、TEM,高分辨透射电子显微镜(HRTEM)以及Raman光谱等分析技术对所制得的碳产物的结构和形貌进行了表征,以研究反应气氛中水蒸气的引入对单壁碳纳米管生长的影响。结果表明:反应气氛的组成对最终所形成的碳产物的产率和结构有着密切的关联。通过控制氢气载入甲烷-氢气-水的混合气氛中水蒸气的量可以合成低无定形碳的洁净单壁碳纳米管。
A Fe2O3/Al2O3 binary aerogel was used as a catalyst for the synthesis of single-walled carbon nanotubes (SWCNTs) by the catalytic decomposition of CH4-H2 and a CH4-H2-water mixture at 900 ℃ for 3 min. The influence of water vapor on the growth of SWCNTs was investigated by characterizing the morphology and structure of the carbon products using scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. Results show that SWCNTs with a high purity were synthesized under the mixed atmosphere of CH4-H2-water when the amount of water vapor present was controlled by bubbling H2 through water. The yield and microstructure of the as-formed carbon products can be correlated with the composition of the reaction mixture.