In this study, preparation of 2 mol% Ce and 4 mol% Co doped TiO2 nanopowders via sol–gel process have been investigated. The effects of Co and Ce doping and calcination temperature (475–1000 C) on the structural and optical properties of titania nanopowders studied by X-ray diffraction (XRD), scanning electron microscope, transmission electron microscope and UV–Vis absorption spectroscope. XRD results showed that, Titania rutile phase formation in ternary system (Ti–Co–Ce) was inhibited by Ce4? and promoted by Co4? co-doped TiO2 in high temperatures (500–700 C) and 61 mol% anatase composition is retained even after calcination at 800 C. The optical absorption spectrum indicates that the TiO2 nanoparticles have a direct band gap of 3.21 eV. But optical band gap of the doped TiO2 (2 mol% Ce and 4 mol% Co) was found to be 3.14–3.20 eV.
