TiO2 nanoparticles loaded with Eu species were prepared with the aim to enhance the photocatalytic activity and to study the activity at different irradiation conditions. TiO2 and Eu3+ doped TiO2 nanostructures were synthesized by hydrothermal method. X-ray diffraction pattern showed a decrease in crystallite size and increase in the crystallinity of the sample on doping with Eu3+. A reduction in the particle size was observed from the SEM and TEM images of Eu3+ doped TiO2 sample. The photocatalytic activity of the undoped and Eu3+-TiO2 nanopowders was estimated towards orange (II) sodium salt (AO7) using natural solar irradiation and UV sources 20 W, 100 W and 400 W respectively. Doping of Eu3+ in TiO2 has significantly improved the photodegradation and decolorization efficiency of the obtained nanostructures.