An anatase film with improved structure of titanium dioxide modified by carbon black

Carbon-modified titanium dioxide (C-TiO2) film of anatase phase was successfully prepared by an improved sol–gel method, of which the sol was mixed with carbon black. It is found that the doped carbon changed the surface morphology and the inner electronic energy state of the TiO2 film. The C-TiO2 film is much rougher than that without doped carbon, indicating a larger specific surface area of the film with more active sits. There are two types of configurations of carbon within the TiO2 film, i.e. the atomistic carbon solid-dissolved in the TiO2 crystal lattice and the particulate carbon involved in the TiO2 film. The solid-dissolved atomistic carbon can lead to additional energy levels to narrow the band gap of TiO2, and the particulate carbon can increase the optical absorption. These can be all utilized to availably enhance the photocatalytic efficiency.