TY - JOUR
T1 - In situ formation of cobalt nanoclusters in sol-gel silica films for single-walled carbon nanotube growth
AU - Wei, Li
AU - Wang, Bo
AU - Liu, Dapeng
AU - Li, Lain Jong
AU - Yang, Yanhui
AU - Chen, Yuan
PY - 2009
Y1 - 2009
N2 - A facile method was developed for in situ formation of Co nanoclusters in sol-gel silica thin films spin-coated on Si wafers. The size and density of Co nanoclusters can be controlled by spin-coating speeds, annealing methods, reduction temperatures under H2, and metal precursor concentrations in tetraethylorthosilicate solutions. The optimized preparation condition, spin-coating speed of 9000 rpm, annealing at 500°C in air followed by reduction at 800°C in H2, resulted in silica films as thin as 60 nm and Co nanoclusters with a mean diameter of 1.5 nm. Morphological and chemical characteristics of thin films and nanoclusters were studied by atomic force microscopy and X-ray photoelectron spectroscopy, respectively. Subsequently, these Co nanoclusters were successfully used to grow SWCNTs by CO decomposition. Film containing Co monometallic clusters produced SWCNTs of 1.3 nm in diameter, whereas film having Co/Mo bimetallic clusters produced SWCNTs of 0.9 nm. This sol-gel approach allowed not only easy catalyst patterning on a thin film but also a fine-tuning of SWCNT properties, e.g., diameter.
AB - A facile method was developed for in situ formation of Co nanoclusters in sol-gel silica thin films spin-coated on Si wafers. The size and density of Co nanoclusters can be controlled by spin-coating speeds, annealing methods, reduction temperatures under H2, and metal precursor concentrations in tetraethylorthosilicate solutions. The optimized preparation condition, spin-coating speed of 9000 rpm, annealing at 500°C in air followed by reduction at 800°C in H2, resulted in silica films as thin as 60 nm and Co nanoclusters with a mean diameter of 1.5 nm. Morphological and chemical characteristics of thin films and nanoclusters were studied by atomic force microscopy and X-ray photoelectron spectroscopy, respectively. Subsequently, these Co nanoclusters were successfully used to grow SWCNTs by CO decomposition. Film containing Co monometallic clusters produced SWCNTs of 1.3 nm in diameter, whereas film having Co/Mo bimetallic clusters produced SWCNTs of 0.9 nm. This sol-gel approach allowed not only easy catalyst patterning on a thin film but also a fine-tuning of SWCNT properties, e.g., diameter.
KW - Co nanocluster
KW - Single-walled carbon nanotube
KW - Sol-gel
KW - Thin film
UR - http://www.scopus.com/inward/record.url?scp=68249154745&partnerID=8YFLogxK
U2 - 10.1142/S1793292009001563
DO - 10.1142/S1793292009001563
M3 - 文章
AN - SCOPUS:68249154745
SN - 1793-2920
VL - 4
SP - 99
EP - 106
JO - Nano
JF - Nano
IS - 2
ER -