Colloidal polymerization of polymer-coated ferromagnetic nanoparticles into cobalt oxide nanowires.
The preparation of polystyrene-coated cobalt oxide nanowires is reported via the colloidal polymerization of polymer-coated ferromagnetic cobalt nanoparticles (PS-CoNPs). Using a combination of dipolar nanoparticle assembly and a solution oxidation of preorganized metallic colloids, interconnected nanoparticles of cobalt oxide spanning micrometers in length were prepared. The colloidal polymerization of PS-CoNPs into cobalt oxide (CoO and Co(3)O(4)) nanowires was achieved by bubbling O(2) into PS-CoNP dispersions in 1,2-dichlorobenzene at 175 degrees C. Calcination of thin films of PS-coated cobalt oxide nanowires afforded Co(3)O(4) metal oxide materials. Transmission electron microscopy (TEM) revealed the formation of interconnected nanoparticles of cobalt oxide with hollow inclusions, arising from a combination of dipolar assembly of PS-CoNPs and the nanoscale Kirkendall effect in the oxidation reaction. Using a wide range of spectroscopic and electrochemical characterization techniques, we demonstrate that cobalt oxide nanowires prepared via this novel methodology were electroactive with potential applications as nanostructured electrodes for energy storage.
Department of Chemistry, University of Arizona, Tucson, Arizona 85721, USA.
Pei Yuin
PY
Keng
Bo Yun
BY
Kim
In-Bo
IB
Shim
Rabindra
R
Sahoo
Peter E
PE
Veneman
Neal R
NR
Armstrong
Heemin
H
Yoo
Jeanne E
JE
Pemberton
Mathew M
MM
Bull
Jared J
JJ
Griebel
Erin L
EL
Ratcliff
Kenneth G
KG
Nebesny
Jeffrey
J
Pyun