A series of novel double perovskite oxides NaMTi2O6 (M = Eu, Sm, and Gd): preparation, characterization and photocatalytic studies under visible and solarlight irradiation

The photocatalytic activity of sol-gel synthesized double perovskite type oxides NaEuTi2O6(NETO), NaSmTi2O6 (NSTO), and NaGdTi2O6 (NGTO) powders on degradation of methylene blue (MB) dye was demonstrated for the first time under visible light as well as sunlight irradiation. The obtained samples were characterized by X-ray diffraction, UV-Visible diffuse reflectance spectroscopy and scanning electron microscopy equipped with X-ray energy-dispersion spectrometry. All the three samples have shown photocatalytic activity for degradation of MB under sunlight and visible light irradiation and their photocatalytic activity followed the order of NGTO > NETO > NSTO. The superior activity of NGTO is ascribed to the higher amount of hydroxyl radicals generated in the photocatalytic reaction.