INOR 65 |
| Incorporation of metal ions into TiO2 has been enhanced photoactivities of TiO2 because of retardation of charge recombination. In this study, the influence of surface and lattice impurities is systematically studied to clarify the role of impurity positions in the photocatalytic activities. Polystyrene microspheres at 180 nm were employed as templates for fabrication of porous TiO2 and lattice-doped V2O5/TiO2 nanoparticles. Surface doped V2O5/TiO2 was then prepared by coating ultra-thin V2O5/TiO2 film onto the surface of porous TiO2 using surface sol-gel method. All samples were calcined at 500°C to remove templates and crystallization. Results showed that anatase and rutile TiO2 were both found, while no vanadium peak appeared in the XRD patterns. The XPS spectra of lattice-doped V2O5/TiO2 clearly showed peaks of Ti(IV) and V(V). In contrast, a Ti(III) peak at 457.1 eV appeared in the surface-doped V2O5/TiO2. Red-shifts from 372 to 405 nm in absorbance edges was observed when vanidum ions were incorporated into TiO2 lattice. In addition, vanadium ions at surface promote the higher photoactivity of TiO2 than those in the lattice for decoloration of Rhodamine B at 305 nm. |
|
Nanoscience: Synthesis and Characterization
8:30 AM-12:10 PM, Sunday, August 19, 2007 BCEC -- 209, Oral
Division of Inorganic Chemistry |