A rapid synthesis of iron phosphate nanoparticles via surface-mediated spontaneous reaction for the growth of high-yield, single-walled carbon nanotubes.
The direct formation of iron phosphate nanoparticles on hydroxyl-terminated SiO(2)/Si substrates with a narrow size distribution (average diameter = 2.2 nm) is achieved by a simple room temperature spontaneous reaction of ferric chloride and phosphoric acid. Single-walled carbon nanotubes (SWNTs) are grown in high yield from the synthesized iron phosphate nanoparticles by the thermal chemical vapor deposition (CVD) method, as confirmed by atomic force microscopy (AFM) and Raman spectroscopy. Furthermore, three-terminal, p-type, nanotube network field effect transistor (FET) devices are successfully fabricated using the synthesized SWNTs via the photolithography technique. The reduced solubility of Fe(III) ions when they form iron phosphate salts in aqueous media is the main driving force for the nanoparticle formation. Systematic control experiments reveal that the surface property, concentration, and pH of the reaction solution play equally important roles in the formation of nanoparticles.
Yang
Hyun Jin
HJ
Department of Chemistry and Pohang Accelerator Laboratory, Pohang University of Science and Technology, San 31, Hyoja-Dong, Nam-Gu, Pohang 790-784, South Korea.
Song
Hyun Jae
HJ
Shin
Hyun Joon
HJ
Choi
Hee Cheul
HC