摘要
采用化学气相沉积法（CVD）以甲烷与氢气为原料，在900℃合成了大量的小直径双壁碳纳米管。我们用硝酸铁和氧化镁粉末的混合物作催化剂，三氧化二铝和钼酸铵作条件催化剂，研究表明条件催化剂的使用有利于双壁碳纳米管的选择性生长，可提高双壁碳纳米管的质量及其在产品中的比例，用扫描电子显微镜（SEM）、高分辨透射电镜（HRTEM）、热失重分析（TGA）和拉曼光谱（Raman）等分析纳米管的形貌和结构，结果发现其内径范围在0．62～0．88nm，外径范围在1．21～1．33nm之间。
Double-walled catalytic chemical vapor carbon nanotubes （DWNTs） with small diameters have been synthesized by deposition at 900℃ under a mixture of methane and hydrogen gas with a conditioning catalyst. The conditioning catalyst is obtained by sonication an ethanol solution containing Al2O3 powder and （NH4）6MoTO24·4H2O. The mixture of Fe （NO3）3·9H2O and MgO powder is used as the catalyst of DWNTs growth. The results shows that the conditioning catalyst can improve the quality and the ratio of DWNTs in the products, and as-synthesized DWNTs have inner tube diameters of 0.62- 0,88 nm and outer tube diameters of 1.21-1.33 nm.
