TiO₂ nanoparticles were synthesized via classical and modified sol-gel method by using titanium isoproxide IV (TIP) as precursor. SEM microscopy showed that particles obtained by modified sol-gel route have spherical morphology, besides X-ray diffraction measurements showed that TiO₂ nanoparticles were polycrystalline with anatase phase. Photocatalytic properties of TiO₂ nanoparticles were evaluated via degradation of methylene blue (MB) in aqueous solution under UV irradiation. The results showed that the titania prepared by modified sol-gel using cationic surfactant CTAB have higher photocatalytic activity than the classical method which employed complex agents.