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.