气体流量对化学气相沉积法制备碳纳米管的影响

用化学气相沉积法裂解乙炔制备无序多壁碳纳米管,以Fe/S iO2粉状物作为催化剂,考察了气体流量等环境因素对碳纳米管生长的影响。通过TEM和SEM分析得出,当N2流量分别为200、500和800 mL/m in时,碳纳米管的平均直径分别为20、36和82 nm,即碳纳米管的直径随着N2流量的升高而增大。当N2流量增加到800mL/m in时,还生成了大量的直径约为20~30 nm的碳纳米球。不通H2制备不出碳纳米管。

Effects of Gas Flow Rate on the Preparation of Multi-walled Carbon Nanotubes Using Chemical Vapor Deposition

Multi-walled carbon nanotubes(MWNT) were synthesized using a method based on chemical vapor deposition catalyzed by iron nanoparticles embedded in mesoporous silica.MWNT were deposited with different gas flow rate so as to systematically investigate the effect of environment on the growth behavior of MWNT.TEM and SEM results showed that the diameter of MWNT was 20 nm,36 nm and 82 nm respectively at N_2 flow rate of 200 mL/min,500 mL/min and 800 mL/min,i.e.,the average diameter increased with the N_2 flow rate.When N_2 flow rate increased to 800 mL/min,many carbon balls of 20～30 nm in diameter were obtained.Moreover,MWNT could not be obtained without H_2 flow.