Uniform Eu3+:CeO2 hollow microspheres formation mechanism and optical performance

The novel Eu3+:CeO2 hollow microspheres are successfully fabricated by a facile and green route, employing the colloidal carbon spheres as sacrificial templates. In the coating process, the large amount of hydrophilic functional groups are beneficial to the adsorption of Ce3+, Eu3+ and OH to form the initial amorphous precursors on the surfaces of the carbon spheres. When heat-treated at appropriate temperature, the carbon spheres in the cores are burned away, while the precursors in the shell crystallize to the Eu3+:CeO2, forming a hollow structure. The Eu3+ ions occupy the Ce sites in the CeO2 lattice, and yield intense red emissions under 340 nm excitation. This material of hollow microspheres may find potential applications in the field of color display. (C) 2012 Elsevier B. V. All rights reserved.