Abstract

Using europium trioxide (Eu₂O₃), ammonium metavanadate (NH₄VO₃), nitric acid and citric acid as main raw materials, the EuVO₄ was prepared by a facile sol-gel method. The prepared samples were characterized by thermogravimetry and differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. Under ultraviolet light, the photocatalytic activities of EuVO₄ were investigated by methyl orange which was used as simulated sewage. The results showed that the pure rare earth perovskite structure EuVO₄ was obtained in the range of calcination temperature of 300 °C∼900. The photocatalytic experiment demonstrated that EuVO₄ is highly photocatalytic active for the degradation of methyl orange under ultraviolet light irradiation. The EuVO₄ particles that calcined at 700 °C were uniform and spherical with an average grain size of about 1 ∼ 2 μm. The photocatalytic performance of sample that calcinated at 700 °C was the best. When the MO of 10 mg/L was degraded for 2 h in presence of EuVO₄, the degradation rate of MO can reach 95%.

摘要

以三氧化铕(Eu ₂ O ₃ )、偏钒酸铵(NH ₄ VO ₃ )、硝酸和柠檬酸为主要原料，采用简便的溶胶-凝胶法制备了EuVO ₄。通过热重和差示扫描量热法（TG-DSC）、X射线衍射（XRD）、扫描电子显微镜（SEM）和傅里叶变换红外（FT-IR）光谱对制备的样品进行表征。在紫外光下，以甲基橙为模拟污水，研究了EuVO ₄的光催化活性。结果表明，在300°的煅烧温度范围内获得了纯稀土钙钛矿结构EuVO ₄C～ 900。光催化实验表明，EuVO ₄在紫外光照射下对甲基橙的降解具有很强的光催化活性。在 700 °C 下煅烧的 EuVO ₄颗粒均匀且呈球形，平均粒径约为 1 ∼ 2 μm。700℃煅烧样品的光催化性能最好。当10mg/L的MO在EuVO ₄存在下降解2小时时，MO的降解率可达95%。