Copper-/Zinc-Doped TiO 2 Nanopowders Synthesized by Microwave-Assisted Sol-Gel Method.

Using the microwave-assisted sol-gel method, Zn- and Cu-doped TiO 2 nanoparticles with an anatase crystalline structure were prepared. Titanium (IV) butoxide was used as a TiO 2 precursor, with parental alcohol as a solvent and ammonia water as a catalyst. Based on the TG/DTA results, the powders were thermally treated at 500 °C. XRD and XRF revealed the presence of a single-phase anatase and dopants in the thermally treated nanoparticles. The surface of the nanoparticles and the oxidation states of the elements were studied using XPS, which confirmed the presence of Ti, O, Zn, and Cu. The photocatalytic activity of the doped TiO 2 nanopowders was tested for the degradation of methyl-orange (MO) dye. The results indicate that Cu doping increases the photoactivity of TiO 2 in the visible-light range by narrowing the band-gap energy.