Optical Properties of TiO2 Nanopowder Doped by Silver (Copper) during Synthesis or PVD Method

Titanium dioxide doped nanopowders were prepared in two ways: (i) by applying a sol-gel method and (ii) by applying the sol-gel synthesis as the first step for pure TiO2 preparation, and next, doped by using magnetron sputtering technique, that is one of a physical vapour deposition method. Silver and copper (Ag, Cu) metals were used as the dopants. Prepared samples were investigated by scanning electron microscope, X-ray diffraction and UV-Vis spectroscopy. The effect of the dopants' nature and the applied doping method were studied. The results showed that each prepared particles are nanocrystalline materials with particles diameter range from 80 nm to 500 nm (depending on the doping method). From optical experiments, it was possible to observe changes in absorbance spectra, which are probably related to interfacial charge transfer and the localized surface plasmon resonance phenomenon.