Impact of nanometal catalysts on the laser vaporization synthesis of single wall carbon nanotubes

Abstract The effects of catalyst particle size on the purity, yield, and purification efficiency of single wall carbon nanotubes (SWCNTs) synthesized via pulsed laser vaporization were investigated. The purity of as-produced SWCNT material synthesized using Ni and Co nanometal (∼13 nm diameter) catalyst particles was compared to material synthesized using conventional micronmetal (2–3 μm diameter) particles. The SWCNT material from nanometal catalysts demonstrated a 50% increase in SWCNT purity as assessed by optical absorption spectroscopy and thermogravimetric analysis (TGA). A change in the thermal oxidation properties was also observed with the nanometal-SWCNTs exhibiting a suppression of the exothermic oxidation of post-synthesis catalyst. Statistical analysis of the TGA residue yielded mean post-synthesis catalyst particle diameters of 18 ± 6 nm and 3 ± 1 nm for the micronmetal and nanometal produced material, respectively. When a thermal oxidation profile was performed, the micronmetal-produced material showed the typical decrease in SWCNT purity with increasing oxidation temperature while the nanometal-produced material showed increasing SWCNT purity with increasing temperature. Overall, the use of nanometal catalysts significantly increases synthesis yield and offers novel thermal oxidation procedures to thermally remove carbonaceous impurities without the aid of acid treatments for the development of potential large-scale purification processing.

[1]  F. Hennrich,et al.  Single-wall carbon nanotubes with diameters approaching 6 nm obtained by laser vaporization , 2002 .

[2]  Jun Chen,et al.  Single wall carbon nanotube paper as anode for lithium-ion battery , 2005 .

[3]  B. Landi,et al.  Thermal Oxidation Profiling of Single-Walled Carbon Nanotubes , 2005 .

[4]  B. Landi,et al.  Effects of Alkyl Amide Solvents on the Dispersion of Single-Wall Carbon Nanotubes , 2004 .

[5]  Ryne P. Raffaelle,et al.  Lithium Ion Capacity of Single Wall Carbon Nanotube Paper Electrodes , 2008 .

[6]  M. Yudasaka,et al.  Production of Large-Diameter Single-Wall Carbon Nanotubes by Adding Fe to a NiCo Catalyst in Laser Ablation , 2004 .

[7]  Jerry D. Harris,et al.  Carbon nanotubes for power applications , 2005 .

[8]  B. Landi,et al.  Effects of carrier gas dynamics on single wall carbon nanotube chiral distributions during laser vaporization synthesis. , 2007, Journal of nanoscience and nanotechnology.

[9]  P. Nikolaev,et al.  Soft-Bake Purification of Single-Walled Carbon Nanotubes Produced by Pulsed Laser Vaporization† , 2007 .

[10]  W. Pompe,et al.  Role of the catalyst particle size in the synthesis of single-wall carbon nanotubes , 2002 .

[11]  Brian J Landi,et al.  Purity assessment of single-wall carbon nanotubes, using optical absorption spectroscopy. , 2005, The journal of physical chemistry. B.

[12]  W. Pompe,et al.  Novel catalysts, room temperature, and the importance of oxygen for the synthesis of single-walled carbon nanotubes. , 2005, Nano letters.

[13]  M. Sanjuán,et al.  Single-Walled Carbon Nanotubes as Electrodes in Supercapacitors , 2004 .

[14]  M. Yudasaka,et al.  Porous target enhances production of single-wall carbon nanotubes by laser ablation , 2000 .