Solubilization and titania nano-coating of carbon nanotubes using titanium (IV) tetrabutoxide

Single-walled and multi-walled carbon nanotubes (CNTs) are soluble in toluene containing titanium (IV) tetrabutoxide and their surface could be successfully covered with an ultrathin TiO₂ layer. AFM, SEM, TEM, XPS, X-ray and TG-DTA analysis indicate the TiO₂ coating on the surface of CNTs through the hydrolysis of bound titanium alkoxid molecules. After calcination at 450-55O°C, the SWNTs were completely decomposed from the composites and crystalline TiO₂ nanotubes that reflect the shape of the SWNTs were formed. From the XPS results of the prepared TiO ₂MWNTs samples, the atomic ratio of Ti to C is circa 1:100, indicating that the coated TiO₂ layer is very thin. The current approach provides a new direction for hybridization of CNTs with TiO₂ that is photocatalytically active in TiO₂/CNTs nanocomposites.