TiO₂/graphene composite photocatalysts have been prepared by a simple liquid phase deposition method using titanium tetrafluoride and electron beam (EB) irradiation-pretreated graphene as the raw materials. The products were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The effects of varying the synthesis parameters such as graphene content, concentration of titanium tetrafluoride solution and irradiation dose were investigated. It was found that the preparation conditions had a significant effect on the structure and properties of the final products. The irradiated graphene was covered with petal-like anatase TiO₂ nanoparticles, which were more uniform and smaller in size than those in products synthesized without EB irradiation-pretreated graphene. The photocatalytic activities of the products were evaluated using the photocatalytic degradation of methyl orange as a probe reaction. The results showed that the products synthesized using EB irradiation-pretreated graphene exhibited higher photocatalytic activities than those using graphene without EB irradiation pretreatment.

Titania nanotubes (TiO₂-NTs) are a potential drug vehicle for use in nanomedicine. To this end, a preliminary study of the interaction of a model cell with TiO₂-NTs has been carried out. TiO₂-NTs were first conjugated with a fluorescent label, fluorescein isothiocyanate (FITC). FITC-conjugated titania nanotubes (FITC-TiO₂-NTs) internalized in mouse neural stem cells (NSCs, line C17.2) can be directly imaged by confocal microscopy. The confocal imaging showed that FITC-TiO₂-NTs readily entered into the cells. After co-incubation with cells for 24 h, FITC-TiO₂-NTs localized around the cell nucleus without crossing the karyotheca. More interestingly, the nanotubes passed through the karyotheca entering the cell nucleus after co-incubation for 48 h. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) were also employed in tracking the nanotubes in the cell. These results will be of benefit in future studies of TiO₂-NTs for use as a drug vehicle, particularly for DNA-targeting drugs.