Controlled synthesis and characterization of large-scale, uniform Dy(OH)_3 and Dy_2O_3 single-crystal nanorods by a hydrothermal method

摘要

Large-scale and uniform Dy(OH)_3 nanorods have been successfully prepared by a simple hydrothermal method. Subsequent thermal decomposition of the as-prepared Dy(OH)_3 nanorods produced Dy_2O_3 nanorods. X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), thermogravimetric analysis (TGA) and differential thermal analysis (DTA) have been employed to characterize the products. XRD and SAED patterns showed the Dy(OH)_3 nanorods were a pure hexagonal phase and single-crystal in nature. FMSEM and TEM images showed that the diameters of the Dy(OH)_3 nanorods ranged from 40 to 50 nm and the lengths ranged from 300 to 500 nm. The Dy_2O_3 nanorods inherited their parents' morphology, but their size is slightly shrunk in comparison with the Dy(OH)_3 nanorods. The formation mechanism of Dy(OH)_3 nanorods is discussed. Photoluminescence measurement shows that the nanorods have two emission peaks around 490 and 575 nm, which should come from the electron transition from ~4F_(9/2) to ~6H_(15/2) levels and ~4F_(9/2) to ~6H_(13/2) levels, respectively.