Carbon doped mesoporous TiO2 was prepared by an improved calcination route. X-Ray diffraction, UV-visible spectroscopy, TEM, X-ray photoelectron spectroscopy and nitrogen adsorption were used to characterize the prepared TiO2 samples. Citric acid was used as not only carbon source but also the pore-forming agent. The photocatalytic activities were tested in the degradation of an aqueous solution of a reactive dyestuff, methylene blue, under both UV and visible light. The carbon doped mesoporous TiO2 prepared by improved calcination route showed much higher photocatalytic activity than that of catalyst prepared by conventional calcination route and neat TiO2 under visible light. A possible mechanism for the photocatalysis was proposed.

Ionic liquid ([Bmim]OH, [Bmim]Br, [Bmim]BF4) modified TiO2 catalysts were prepared by hydrothrmal method. XRD and UV-visible spectra were used to characterize the prepared composite materials. Ionic liquid modification did not change the crystalline structure of TiO2 particles but reduced the particle size. [Bmim]OH modified TiO2 shows the obviously enhanced visible light absorption. The influence of ionic liquid types, modification amount, reactant concentration and pH value on the photocatalytic activity of TiO2 catalyst under visible light were investigated.