Noncovalent titania wrapping of single-walled carbon nanotubes for environmentally stable transparent conductive thin films

Abstract

We present a simple process for the fabrication of high performance transparent conducting films that contain single-walled carbon nanotubes (SWCNTs) noncovalently coated with an ultrathin titania layer. The hydrophobic interactions between nanotube surfaces and the acetylacetone (acac) ligands used to stabilize the TiO₂ precursor provide an interesting alternative method for noncovalently coating the SWCNTs with a titania layer. The ultrathin titania layer on SWCNTs prevented the oxidation of functionalized SWCNTs at high temperatures, and protected against water molecule absorption. Moreover, the uniform and thin titania layer, formed via hydrophobic interactions, promoted the selective removal of amorphous carbonaceous materials upon heating to 300 °C as well as withdrawing electrons from the nanotubes. The noncovalent titania coating of the SWCNTs may potentially exhibit other interesting physical properties relevant to applications such as transparent conducting films, photo-catalysis, and sensor electrodes.