Titania (TiO2) photocatalyst was synthesized by the sol-gel method involving acid hydrolysis followed by oxidation with hydrogen peroxide. Cobalt and nickel metal ions were impregnated at 1, 5 or 10 % concentrations using metal nitrate salt solutions. The photocatalysts were characterized by various techniques. Scanning Electron Microscopy (SEM) and Diffused Reflectance Spectroscopy (DRS) showed that the doped TiO2 were smaller in size and had smaller band gap than pure TiO2, while X-ray Diffraction (XRD) and X-ray Fluorescence (XRF) spectroscopy showed that all the photocatalysts were rutile phase and contained the expected elements. The percent degradation of Picric acid dye at pH 3, initial dye concentration 10 ppm, catalyst concentration 0.10 g/l, and temperature 55 oC, had rank order: TiO2 < 1 % doped < 5 % doped < 10 % doped TiO2, showing that the photocatalytic activities of the Co-TiO2 and Ni-TiO2 increased with dopant concentration.
