Facile synthesis and luminescence of GdPO4:Eu hollow microspheres by a sacrificial template route

In this work, we report a facile synthesis of highly uniform and well-dispersed GdPO4:Eu3+ hollow microspheres (around 2.1 mu m) via a urea-based homogeneous precipitation technique with colloidal melamine formaldehyde (MF) microspheres as templates and NH4H2PO4 as a phosphorus source without calcination process. X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) results show that the MF templates can be effectively removed, and the precursor Gd2O(CO3)(2)center dot H2O:Eu3+ has also converted to crystalline GdPO4:Eu3+ during the hydrothermal process. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images indicate that the GdPO4:Eu3+ hollow spheres inherit a spherical shape and good dispersion of MF template, and the thickness of the shell is about 180 nm. In addition, Eu3+ doped GdPO4 hollow spheres exhibit strong orange-red emission, corresponding to the characteristic transitions of D-5(0)-> F-7(1), 2, 3, 4 of Eu3+, with D-5(0)-> F-7(1) transition as the most prominent group. Furthermore, this synthesis route may be of great significance in the preparation of other hollow phosphate spherical materials. (C) 2013 Elsevier B.V. All rights reserved.