Papers by Keyword: Sm₂O₃

Abstract: In this study ZnO photocatalysts with different loading of Eu₂O₃ and Sm₂O₃ were prepared vie microwave-assisted hydrothermal method. The prepared samples were investigated by using XRD, SEM and BET analysis. The photocatalytic activity was determined by degradation of methylene blue (MB) under Osram Vitalux illumination. Prepared ZnO photocatalysts shown high photocatalytic activity under solar light simulated radiation. After 30 minute of irradiation more than 95 % of initial MB solution was degraded. The effect of pH and photocatalyst dosage was investigated. The reusability of photocatalysts was also studied.

Abstract: Spherical Sm₂O₃ nanoparticles have been successfully synthesized by microwave-assisted hydrothermal technique in the condition of different microwave radiation power. The microstructure, morphology and optical properties of the samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), field emission transmission electron microscope (FETEM) and ultraviolet-visible (UV-vis) spectrophotometry. The results showed that the precursors Sm (OH)₃ nanorods and SmOHCO₃ nanoparticles were obtained during microwave-assisted hydrothermal reaction and decomposed into spherical Sm₂O₃ nanoparticles after heat treatment. A potential mechanism of the formation of Sm₂O₃ nanoparticles is proposed. The UV-vis absorption spectra indicated that the samples had high ultraviolet absorption capacity and the energy gap was only 4.83 eV as the radiation power increased to 550 W.

Abstract: In this study, the effect of Sm³⁺ ions doped in glasses of the composition (40-x)B₂O₃:40Bi₂O₃:20BaO:xSm₂O₃ in mol% (where x = 0, 0.50, 1.00, 1.50, 2.00 and 2.50).The BiBaBO glasses have been prepared by melt-quench technique. The results show the densities and molar volume of glasses are between 4.80-4.91 g/cm³ and 50.19-51.58 cm³/mol, respectively. The absorption spectra consists of ten absorption peaks that are located at 374, 388, 402, 942,1079, 1226, 1405, 1471, 1523 and 1585 nm, and are assigned to ⁶P_7/2, ⁴G_11/2, ⁶P_3/2, ⁶F_11/2, ⁶F_9/2, ⁶F_7/2, ⁶F_5/2, ⁶F_3/2, ⁶H_15/2 and ⁶F_1/2 transitions, respectively. The luminescence spectra exhibited four emission peaks corresponding to the ⁴G_7/2 → ⁶H_5/2 (564 nm yellow, weak), ⁴G_7/2 → ⁶H_7/2 (600 nm orange, strong), ⁴G_7/2 → ⁶H_9/2 (645 nm red, strong) and ⁴G_7/2 → ⁶H_11/2 (709 nm red, weak) transitions.

Abstract: Nanofiber is an important part in nanomaterials research field, and the polymer nanofibers is one of the important research directions. RE, which has unique electronic structure, the optical, electrical and magnetic aspects of the special nature, combine with the polymer, that has rich raw materials, simple synthesis method, easy processing, high impact resistance, light weight and low cost advantages, to get a new kind materials of practical uses and potential applications. This topic was prepared PVA/Sm (NO₃)₃ composite nanofibers using an electrostatic spinning, and the PVA/Sm (NO₃)₃ nanofibers were treated at an appropriate temperature to obtain Sm₂O₃ nanofibers. Samples were characterized and analyzed by the SEM, FTIR, XRD, TG-DTA and other modern means. The results show that the surface of PVA/Sm (NO₃)₃ composite fibers is smooth, uniform size and amorphous. Sm (NO₃)₃ is not interact with the PVA groups, and the diameter of fiber is 200nm. After firing, the diameter of fibers was reduced to 100nm. PVA, Sm (NO₃)₃ and the water are completely decomposed at 600°C or more, finally obtained Sm2O3 nanofibers of single-phase crystalline state.

Abstract: Sm2O3 optical thin films were prepared by hydrothermal method using samarium dichloride as source material. The influence of preparation temperature on the crystallinity, morphology and optical properties of Sm2O3 thin film were investigated. The as-fabricated thin films were characterized by X-ray diffraction, atomic force microscopy and spectrophotometer. Results show that the prepared thin film is Sm2O3 crystallites thin film with compact and uniform surface microstructures. Transmittance curve displays that the Sm2O3 crystallites thin films are transparent to visible and infrared light; and possess excellent absorbency of UV light. With the increase of deposition temperature, the crystallinity and optical properties of the prepared Sm2O3 thin film are improved. With the increase of hydrothermal temperature from 170 °C to 185 °C, the bandgap of the thin film increase from 2.88 eV to 2.95 eV.