Preparation of EuVO4 by Hydrothermal Method and Its Photocatalytic Activity

Using europium trioxide(Eu2O3), ammonium metavanadate(NH4VO3), nitric acid, ammonium hydroxide and citric acid hexahydrate, the EuVO4 was prepared by hydrothermal method. The structure and morphology of samples were characterized by thermogravimetry and differential scanning calorimetry (TG-DSC), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and UV-visible diffuse reflectance spectroscopy (DRS). Using methyl orange as simulated sewage, the visible-light photocatalytic activities of EuVO4 were investigated on synthesis temperatures and illumination time. The results showed that the purely rare earth perovskite structure EuVO4 was prepared in the range of hydrothermal temperature of 120 ∼ 180 °C. The EuVO4 particles are uniform size prepared in 140 °C, which have a particle size of 2 ∼ 4 μm and an optical band gap of 2.07 eV. The photocatalytic experiment demonstrates that hydrothermal synthesis at 140 °C is the best. Under visible-light irradiation, the degradation rate methyl orange of 10 mg/L can reach 93% for 60 min. The EuVO4 shows excellent photocatalytic activities.