TY - JOUR
T1 - Synthesis of helical carbon nanotubes, worm-like carbon nanotubes and nanocoils at 450 °C and their magnetic properties
AU - Qi, Xiaosi
AU - Zhong, Wei
AU - Deng, Yu
AU - Au, Chaktong
AU - Du, Youwei
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China ( Grant No. 10674059 ), the National High Technology Research and Development Program of China ( Grant No. 2007AA021805 ), and the National Key Project for Basic Research ( Grant No. 2005CB623605 ), People’s Republic of China.
PY - 2010/2
Y1 - 2010/2
N2 - High purity (99.21 wt.%) helical carbon nanotubes (HCNTs) were synthesized in large quantity over Fe nanoparticles (fabricated using a coprecipitation/hydrogen reduction method) by acetylene decomposition at 450 °C. Field-emission and transmission electron microscope images reveal that the selectivity to HCNTs (with two or three coiled nanotubes connected to a catalyst nanoparticle) is up to ca. 93%. The yield of HCNTs (as defined by the equation: yield = frac(mtotal - mcatalyst, mcatalyst) × 100 %) is ca. 7474% in a run of 6 h, higher than any of those reported in the literature. If hydrogen was introduced during acetylene decomposition for ca. 30 min, the HCNTs mainly consisted of two coiled tubes connected to a catalyst nanoparticle, and carbon nanocoils (CNCs) of different structures were generated. If hydrogen was present throughout acetylene decomposition, worm-like carbon nanotubes (CNTs) as well as CNCs were produced in large quantities. Because the HCNTs and worm-like CNTs are attached to Fe nanoparticles, the nanomaterials are high in magnetization. Crown
AB - High purity (99.21 wt.%) helical carbon nanotubes (HCNTs) were synthesized in large quantity over Fe nanoparticles (fabricated using a coprecipitation/hydrogen reduction method) by acetylene decomposition at 450 °C. Field-emission and transmission electron microscope images reveal that the selectivity to HCNTs (with two or three coiled nanotubes connected to a catalyst nanoparticle) is up to ca. 93%. The yield of HCNTs (as defined by the equation: yield = frac(mtotal - mcatalyst, mcatalyst) × 100 %) is ca. 7474% in a run of 6 h, higher than any of those reported in the literature. If hydrogen was introduced during acetylene decomposition for ca. 30 min, the HCNTs mainly consisted of two coiled tubes connected to a catalyst nanoparticle, and carbon nanocoils (CNCs) of different structures were generated. If hydrogen was present throughout acetylene decomposition, worm-like carbon nanotubes (CNTs) as well as CNCs were produced in large quantities. Because the HCNTs and worm-like CNTs are attached to Fe nanoparticles, the nanomaterials are high in magnetization. Crown
UR - http://www.scopus.com/inward/record.url?scp=70449523677&partnerID=8YFLogxK
U2 - 10.1016/j.carbon.2009.09.038
DO - 10.1016/j.carbon.2009.09.038
M3 - Journal article
AN - SCOPUS:70449523677
SN - 0008-6223
VL - 48
SP - 365
EP - 376
JO - Carbon
JF - Carbon
IS - 2
ER -