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

Abstract In this work, we report a facile synthesis of highly uniform and well-dispersed GdPO 4 :Eu 3+ hollow microspheres (around 2.1 μm) via a urea-based homogeneous precipitation technique with colloidal melamine formaldehyde (MF) microspheres as templates and NH 4 H 2 PO 4 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 Gd 2 O(CO 3 ) 2 ·H 2 O:Eu 3+ has also converted to crystalline GdPO 4 :Eu 3+ during the hydrothermal process. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images indicate that the GdPO 4 :Eu 3+ hollow spheres inherit a spherical shape and good dispersion of MF template, and the thickness of the shell is about 180 nm. In addition, Eu 3+ doped GdPO 4 hollow spheres exhibit strong orange–red emission, corresponding to the characteristic transitions of 5 D 0 → 7 F 1 , 2, 3, 4 of Eu 3+ , with 5 D 0 → 7 F 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.