Enhanced photocatalytic activity of nano titanium dioxide coated on ethanol-soluble carbon nanotubes

Surface functionalized carbon nanotubes (CNTs) with ethanol solubility were synthesized and the CNTs–TiO2 nanocomposites were prepared by coupling of TiO2 with modified CNTs through a sol–gel method. The as-prepared CNTs and composites were characterized and the composite samples were evaluated for their photocatalytic activity toward the degradation of aqueous methyl orange. It is showed that the acid oxidation of CNTs leads to the embedding of oxygenated functional groups, and as a result, the acid-treated CNTs in turn may serve as chemical reactors for subsequent covalent grafting of octadecylamine. Improved photocatalytic performance of CNTs–TiO2 composites was obtained, which is mainly attributed to the high dispersion of TiO2 on ethanol-soluble CNTs and the intimate contact between TiO2 and CNTs resulted from the dense heterojunctions through the TiOC structure at the interface between TiO2 and CNTs.