载气种类对单壁碳纳米管管径的影响研究

单壁碳纳米管的管径对其性能、特别是储氢性能有极其重要的影响,但至今未见制备过程中系统控制单壁碳纳米管管径的报道.本文分别以氦气、氮气和氩气为载气,采用催化裂解法制备了不同直径范围的单壁碳纳米管.HRTEM和Raman光谱分析表明,以氦气、氩气为载气制得的碳管直径分布范围相对较窄,平均直径分别约为1.6和5.0nm.以氮气为载气时碳管直径分布相对较宽,约为2.0～4.5nm.氮气与碳反应生成氮化碳可能是导致单壁碳纳米管直径分布相对较宽的主要原因.分别以氦气、氮气和氩气为载气制得的单壁碳纳米管,在273K,15MPa时质量储氢分数依次为4.21%、6.30%和8.05%.

Study on the effect of the type of carrier gas on the diameter of single-walled carbon nanotube

The diameter of single-walled carbon nanotube has very significant effect on its properties, especially hydrogen storage property. However, no result has been reported about controlling the diameter systematically during the preparation of SWNT so far. Single-walled carbon nanotubes with different diameter were synthesized successfully by catalytic pyrolysis method when helium, nitrogen and argon was used as carrier gas, respectively. It was revealed by HRTEM and Raman spectrum analysis that SWNT synthesized with helium and argon as carrier gas had relatively narrow diameter distribution, with 1.6nm and 5.0nm respectively and SWNT synthesized with nitrogen as carrier gas had relatively wide diameter distribution, from 2.0-4. 5nm. The formation of carbon nitride was probably the main reason for the growth of SWNT with wide diameter distribution. SWNT synthesized with helium, nitrogen and argon as carrier gas had mass fraction of hydrogen storage of 4.21%, 6.30% and 8.05% respectively at 273K and 15MPa.