Nitrogen-doped titanium dioxide (N-TiO2) powders were synthesized by hydrolysis and used as a support for doping with various metals, such as, Fe, Cr, Ni, and Pt. Aqueous solutions of metal salts were used as a metal source and metals were deposited on N-TiO2 powders. Ni-N-TiO2 catalysts with various nickel concentrations were studied in detail. X-ray diffraction and diffuse reflectance spectrophotometry were used for the characterization of the photocatalysts. The Ni-N-TiO2 photocatalysts were then tested in photocatalytic water splitting under visible light. The optimum dopant concentration was found to be 10 mu mol Ni/g N-TiO2 for Ni-N-TiO2. The photocatalyst, Ni-N-TiO2, has shown a stable and high activity, 490 mu mol of H-2 g(cat)(-1) h(-1) for the first 6 h of operation.