Preparation of luminescent nanosized NaEu(MoO4)2 incorporated in amorphous matrix originated from zeolite

Novel luminescent material has been prepared by the reaction of Eu3+ and molybdate species in the matrix of faujasite (FAU) type zeolite X and successive calcination. Eu3+ exchanged FAU was reacted with MoO3 in the solid-state at 723 K, giving a precursor. By calcining it at 1073 K, different crystalline phases were derived depending on MoO3-loading levels. Scheelite type crystal of NaEu(MoO4)2 was formed at high MoO3-loading levels, whereas europium sodalite was formed at low loading levels. For the former sample, X-ray diffraction analysis and transmission electron microscopy revealed that the nanosized NaEu(MoO4)2 was dispersed homogeneously within amorphous aluminosilicate matrix originated from FAU. The amorphous particles containing NaEu(MoO4)2 maintained the original morphology, which the starting FAU particles possessed. The emission intensity of nanosized NaEu(MoO4)2 in the matrix was one order higher than that of europium sodalite. The emission lifetime of nanosized NaEu(MoO4)2 (0.39 ms) in the matrix was longer than that of bulk NaEu(MoO4)2 (0.35 ms) fabricated by conventional solid-state processes.