Facile selective synthesis and luminescence behavior of hierarchical NaY(WO4)2:Eu3+ and Y6WO12:Eu3+

Abstract

Two kinds of Eu³⁺-doped tungstate precursors with uniform bowknot and flower morphologies have been synthesized with the assistance of disodium ethylenediamine tetraacetate (Na₂H₂L). The precursors with distinct morphologies and constituents were obtained selectively by simply changing the amount of the identical reagents. After calcinations, the precursors were successfully transformed into morphology-preserved Eu³⁺-doped NaY(WO₄)₂ and Y₆WO₁₂ respectively. The formation of these structures was proposed based on the evolution of the morphology. Under UV excitation, the bowknot-like precursor of NaY(WO₄)₂ exhibits white emission due to a broad band and the characteristic transitions of Eu³⁺ ions, while both the annealed products show strong red emission when excited at the O–W charge transfer band.