Carbon nanotubes supported mesoporous mesocrystals of anatase TiO 2

Abstract

Carbon nanotubes (CNTs) and titanium dioxides (TiO2) are among the most studied functional materials in recent years. In this work, we have developed a one-pot chemical approach to prepare mesocrystals of anatase TiO2 onto multiwalled CNTs with controllable surface coverage, surface area, crystal orientation, and TiO2/CNTS ratio. Under mild reaction conditions (at 60 °C and slightly higher than 1 atm), [001]-oriented petal-like TiO2 mesocrystals have been evenly grown onto CNTs in aqueous solution. The overlayer metal-oxide phase has crystallite sizes of 2-4 nm and a very uniform size of mesopores centered at 2.5 nm. Some possible mechanisms for pore formation under this surfactant-free condition are discussed. Our investigation also indicates that the CNTs supported mesocrystals of anatase TiO2 can be used as composite catalysts, and they have been proved to be highly active and robust for photocatalytic degradation of methyl orange, without any additional treatments. © 2008 American Chemical Society.