Characterization and Photocatalytic Activity of SmMnO3 Prepared by Sol-Gel Process

Using samarium (III) nitrate hexahydrate, manganese nitrate and citric acid as main raw materials, the SmMnO3 gel was prepared by sol-gel process. The gel was kept at 100 °C for 24 h to get the xerogel. Then, the xerogel was respectively calcined in muffle furnace at 600 °C, 700 °C, 800 °C and 900 °C. The structure and morphology of samples were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier Transform Infrared (FT-IR) spectroscopy. The UV photocatalytic activities of SmMnO3 were investigated by methyl orange which was used as simulated sewage. The results show that the pure SmMnO3 can be obtained through calcination between 700 °C and 800 °C, and the SmMnO3 have an average particle size of 80 nm. The SmMnO3 samples calcined at 700 °C and 800 °C show high photocatalytic activity for decomposition of methyl orange under UV-light irradiation. The SmMnO3 samples are consistent with first-order kinetics for the degradation of methyl orange. And the apparent rate constants are respectively k700 =0.01206 min-1and k800=0.01088 min-1.