单壁碳纳米管在基底表面的离散生长

Discrete Growth of Single-walled Carbon Nanotubes on Surfaces

通过旋涂硝酸铁异丙醇溶液于P型硅表面以获得均匀分布的催化剂颗粒,以CH4为反应气体采用CVD方法即可在P型硅表面均匀生长单壁碳纳米管,并且部分碳纳米管呈直立状。研究了催化剂浓度、生长基底、反应温度对单壁碳纳米管表面生长情况的影响。研究表明,催化剂浓度升高或采用二氧化硅替代P型硅为生长基底时,都会导致单壁碳纳米管生长的密度加大,而碳纳米管长度变短且更易贴附基底表面生长;随反应温度的提高碳纳米管的生长效率降低,并使得碳纳米管更易贴附基底表面生长。采用此方法制备的生长有直立碳纳米管的硅片作为扫描基底,在原子力显微镜敲击模式下利用拾取法成功制备了碳纳米管原子力显微镜针尖。

Catalyst particles were obtained by spin-coating isopropyl alcohol solution of Fe（NO3 ）3 on surface of P-type silicon. These particles can catalyze the decomposition of CH4 and growth of single- walled carbon nanotubes （SWNTs）. On surface of P-type silicon, the distribution of SWNTs is uniform and some of SWNTs are erect. The influences of concentration of catalyst, substrates, reaction temperatures were investigated. Increase in catalyst concentration or silicon dioxide replacing P-type silicon as substrate could lead to denser SWNTs, shorter SWNTs and decrease in erect SWNTs on surface. With higher reaction temperature, growth of SWNTs is with lower efficiency and with higher probability to be affixed on surface of substrate. By pick-up method, carbon nanotube Atomic Force Microscopy（AFM） tips were successfully fabricated by imaging the nanotubes-covered substrates in tapping mode of AFM.