Phosphors with different morphology, formed under hydrothermal conditions on the basis of ZrO2:Eu3+ nanocrystallites

Abstract

Eu 3+-doped ZrO 2 nanostructures in the form of rods, stars, and hollow spheres were prepared by varying hydrothermal conditions. X-ray diffraction, transmission electron microscopy, ultraviolet-visible diffuse reflection spectroscopy, a low-temperature nitrogen adsorption method, Raman spectroscopy and photoluminescence spectra were used to characterize the polymorph modification, surface and optical properties of the Zr 0.98 Eu 0.02 O 2 nanophosphors. The Eu 3+ content in a zirconia monoclinic lattice, remained constant for all types of obtained nanostructures in order to reveal the morphology influence on the efficiency of electronic excitation energy transfer from the host matrix to photoactive centers. The decrease of the average size of the coherent scattering regions in the series rods → stars → hollow spheres, is associated with increasing the specific surface area values. At that, in the photoluminescence spectrum, the splitting of the sublevels associated with the monoclinic lattice 5 D 0 → 7 F 1 disappears.

Synergistic Effect of Metal Oxide and Carbon Nanoparticles on the Thermal and Mechanical Properties of Polyimide Composite Films

“…Then, the steel autoclave was hermetically sealed, heated at a rate of 5 °C/min, and kept at 250 °C for 4 h. The ZrO 2 nanoparticles formed were removed from the autoclave, dried at 100 °C and cooled to room temperature naturally. The powder was characterized using a set of methods of physicochemical analysis [ 62 ]. The presence of the hydroxyl groups on the surface of the nanoparticles was confirmed by FTIR spectroscopy ( Figure S1 ).…”

Synthesis and characterization of zirconia nanorods as a photo catalyst for the degradation of methylene blue dye

“…Because of its photochemical stability, high refractive index, large band gap, transparency in the visible and near-infrared regions of the spectrum, and low phonon energy, zirconia is the best optical medium for lanthanide ions among p-type semiconductors. It also has a low phonon energy, which reduces the likelihood of nonradiative transitions due to multiphonon relaxation [31]. Zirconia (ZrO 2 ) has a high bandgap energy and is a chemically stable material.…”