Tuning the architecture and properties of microstructured yttrium tungstate oxide hydroxide and lanthanum tungstate

Abstract

In this paper, various microstructures of yttrium and lanthanum tungstates were synthesized under hydrothermal conditions, at pH 5, in a ligand-free environment, and in the presence of a dioctyl sodium sulfosuccinate (DSS) surfactant. It was observed that the shape of the nanobuilding blocks, and therefore the architecture of the microstructures, could be tuned by controlling the reaction conditions, such as the source of the rare earth, the amount of a surfactant and the reaction time. X-ray powder diffraction (XRD), elemental analysis, scanning electron microscopy (SEM), and N₂ adsorption were employed to characterize the obtained products. The photoluminescent properties of Eu³⁺ and Dy³⁺ doped tungstate materials were investigated. Luminescence measurements showed an efficient charge transfer from the WO₄²⁻ groups to Eu³⁺ and Dy³⁺ ions. It was found that under UV excitation the Dy³⁺ doped Y(WO₃)₂(OH)₃ and La₂(WO₄)₃ precursors exhibit white emission.