Synthesis of Carbon Materials-TiO₂ Hybrid Nanostructures and Their Visible-Light Photo-catalytic Activity

Activated carbon, graphene, carbon nanotubes and fullerene were incorporated into TiO₂ by a solvothermal approach and thermal annealing to produce carbon materials-TiO₂ hybrid nanostructures. The carbon materials-TiO₂ products were characterised by using SEM, TEM, XRD, Raman spectroscopy, X-ray photo-electron spectroscopy, UV-visible spectroscopy and photo-luminescence. The aim was to study the interactions between the main TiO₂ phase and the carbon components, and the relationships between morphology, structure and photo-degradation of the rhodamine B (RhB) dye. An enhanced photo-catalytic degradation of RhB was achieved when using these nanocomposites over that for only using pure TiO₂ . The superiority in photo-catalytic activities on the RhB molecules resulted from contributions from the excellent adsorption property, favourable chemical bond formation (TiOC), narrower band gap, smaller particle size and effective charge-carrier separation of the nanocomposites. Compared with the graphene-, carbon nanotube- and fullerene-TiO₂ products, activated carbon-TiO₂ exhibited weaker interactions between carbon and titania, lower adsorption for RhB and a larger band gap, which led to lower photo-catalytic activity of RhB.