Hydrothermal Synthesis and Luminescence Properties of CePO4∶Tb Core-shell Microspheres

Abstract

Tb3+-doped CePO4 core-shell microspheres with diameter of 2~3 μm were hydrothermally synthesized at pH=1.0 without using any template or surfactant. It was observed that the shells of these spheres were composed by nanorods with a diameter of about 20~30 nm and lengths up to 200~300 nm. The time-dependent experiments were also carried out to investigate their growing process. Initially, aggregated spherical products were formed. Then, some particles grew on its surface. As a result of Ostwald ripening, the size of the product increased. Finally, at the expense of the cores inside the spheres, the surface of the product experienced a change from nanoparticles to nanorods. The luminescent properties and luminescence decay lifetimes of CePO4∶Tb core shell microspheres were performed, indicating that the strongest emission intensity was reached with 10% molar fraction of Tb3+ ions, which might be ascribed to the concentration quenching effect.