Graphene oxide/TiO(2) composites were prepared by using TiCl(3) and graphene oxide as reactants. The concentration of graphene oxide in starting solution played an important role in photoelectronic and photocatalytic performance of graphene oxide/TiO(2) composites. Either a p-type or n-type semiconductor was formed by graphene oxide in graphene oxide/TiO(2) composites. These semiconductors could be excited by visible light with wavelengths longer than 510 nm and acted as sensitizer in graphene oxide/TiO(2) composites. Visible-light driven photocatalytic performance of graphene oxide/TiO(2) composites in degradation of methyl orange was also studied. Crystalline quality and chemical states of carbon elements from graphene oxide in graphene oxide/TiO(2) composites depended on the concentration of graphene oxide in the starting solution. This study shows a possible way to fabricate graphene oxide/semiconductor composites with different properties by using a tunable semiconductor conductivity type of graphene oxide.

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The visible-light-induced self-cleaning property of cotton has been realized by coating N-TiO(2) film and loading AgI particles simultaneously. The physical properties were characterized by means of XRD, SEM, TEM, XPS, and DRS techniques. The visible light photocatalytic activities of the materials were evaluated using the degradation of methyl orange. In comparison with TiO(2)-cotton, the dramatic enhancement in the visible light photocatalytic performance of the AgI-N-TiO(2)-cotton could be attributed to the synergistic effect of AgI and N-TiO(2), including generation of visible light photocatalytic activity and the effective electron-hole separations at the interfaces of the two semiconductors. The photocatalytic activity of the AgI-N-TiO(2)-cotton was fully maintained upon several numbers of photodegradation cycles. In addition, according to the XRD patterns of the AgI-N-TiO(2)-cotton before and after reaction, AgI was stable in the composites under visible light irradiation. Moreover, a possible mechanism for the excellent and stable photocatalytic activity of AgI-N-TiO(2)-cotton under visible light irradiation was also proposed.

Photocatalytic anatase TiO2 nanowire thin films have been prepared by in situ oxidation of Ti plate in a mixture solution of concentrated H(2)O(2) and NaOH, followed by proton exchange and calcination. The morphologies and properties of the titanate and titania films have been investigated by means of field emission scanning electron microscopy, energy-dispersive x-ray spectrometry, high resolution transmission electron microscopy, x-ray diffraction and Raman spectrometry. The mechanism of formation of the porous microstructure has been discussed; it is the result of the balance between dissolution and precipitation. And sodium ions in the solution are needed to combine with titanate species for the nanowire formation. The anatase TiO2 nanowire thin films exhibited enhanced photocatalytic activity and stability in phenol degradation. The combination effects of the porous morphology and nanowire characteristics are favorable for improved photocatalytic performance. This novel nanowire film is promising for practical aqueous purification.

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