Fabrication and Characterization of Indium Tin Oxide-Carbon Nanotube Nanocomposites

Nanocrystals of two indium tin oxide (ITO) polymorphs (rhombohedral and cubic) were deposited on the sidewalls of the multiwalled carbon nanotubes (MWCNTs) by a simple coprecipitation process. X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscope (HRTEM) images, select area electron diffraction patterns (SAED), and energy-dispersive X-ray (EDX) spectroscopy were used to characterize the as-prepared samples. The results indicated that tuning of the ITO phase in the nanocomposites can be selectively achieved via controlling the pH value of the coprecipitation process and the temperature of the subsequent calcination. The formation mechanism of the ITO/MWCNT nanocomposites was also investigated. Electrical conductivity measurements on the samples pressed into pellets showed that the maximum conductivities attained were 0.52 +/- 0.05 and 0.65 +/- 0.04 S.cm(-1) for the rhombohedral and cubic ITO/MWCNT nanocomposites, respectively, at a dopant concentration of 12.5 wt %. The electrical conductivity of the nanocomposites was significantly enhanced compared to the pristine MWCNTs.