Abstract
Titanium dioxide(TiO2) is an important materials for photocatalytic applications.In this thesis,we have investigated the effects of impurity doping and thermal annealing on visible-light absorption of TiO2. Nanoparticles of Cobalt- and Zirconium-doped titanium dioxide, as well as (Co, Zr) co-doped TiO2, were synthesized by sol-gel method followed by thermal annealing at 500 degrees Celsius and 800 degrees Celsius. The crystal structures of the samples were probed by X-ray diffraction and then reconfirmed by Raman spectroscopy. Extended x-ray absorption fine structure analysis shows that the dopant atoms substitute for titanium sites in TiO2. Visible-light absorption properties and band gaps for all samples were determined by using an ultraviolet-visible spectrometer. We observed enhanced visible-light absorption in 500 degrees Celsius-annealed (Co,Zr) co-doped TiO2 due to defects and impurities.