Immobilization of TiO2 films on activated carbon fiber and their photocatalytic degradation properties for dye compounds with different molecular size

A series of TiO2/ACF samples were prepared by sol–gel-adsorption method and were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and nitrogen adsorption. SEM showed that calcined temperature had an important influence on final structure morphologies of TiO2 films. XRD analysis implied that all samples presented anatase structure, carbon surfaces located under TiO2 film could influence the crystalline degree of TiO2. Nitrogen adsorption measurement indicated that some pores located in activated carbon fiber (ACF) were covered by TiO2 film. Photocatalytic degradations of methyl orange solution and acid fuchsine solution showed that dye compounds could be removed rapidly from water by TiO2/ACF samples because of dual functions: absorption of ACF and photocatalytic degradation of TiO2 film, and there was a matched relation between pore diameter of immobilized sample and molecular size of dye compound.