气凝胶催化剂上甲烷裂解制备的碳纳米管结构特征

Structure of Carbon Nanotubes from Decomposition of Methane on an Aerogel Catalyst

采用XRD、TGA、SEM、TEM、Raman光谱等多种表征手段,考察了Al2O3气凝胶催化剂上甲烷裂解生长的碳纳米管的结构特征.制得的碳纳米管形态单一,为管径均匀、管壁光滑的中空纳米管,平均直径在10～20nm.碳纳米管的比表面积较大,具有较强的抗氧化能力,其结构的长程有序度较石墨低.由碳纳米管的Raman光谱分析可知,碳纳米管存在碳层缺陷和无定形碳.当反应温度升高或甲烷浓度下降时,碳纳米管石墨化程度逐渐提高.

Carbon nanotubes were prepared from catalytic decomposition of methane on an aerogel catalyst. The structure of carbon nanotubes was characterized by XRD, TGA, SEM, TEM and Raman spectroscopic methods. The carbon nanotubes grown on the aerogel catalysts are hollow with smooth wall and even diameters. The average diameter of the tubes is in the range of 10 similar to 20 mn. The nanotubes obtained in this work have a large surface area and a good oxygen resistance. From the Raman spectra of carbon nanotubes grown on the aerogel catalysts, it was observed that the nanotubes prepared with this method contained defects in the graphene layers and contained amorphous carbon. Carbon species become more graphitic when reaction temperature increases or concentration of methane decreases.