Sol-gel derived B (boron) and Zr (zirconium) doped TiO2 (Titania) nanoparticles were synthesized. Microstructural, photocatalytic and crystallographic properties of the doped particles were investigated. Highest photocatalytic activity was achieved by 10 wt% Zr doping. 5 wt% doping was the optimum value for effective B doping. B ions were found to form oxygen vacancies behaving as interstitial defects whereas Zr ions substituted Ti4+ ions in the lattice.