Tb^(3+)掺杂CePO_4核壳微球的水热合成及其发光性能

Hydrothermal Synthesis and Luminescence Properties of CePO_4:Tb Core-shell Microspheres

在pH=1无模板条件下水热合成出直径为2～3μm的CePO4∶Tb核壳微球结构。其核壳表面由直径为20～30 nm、长度为200～300 nm的纳米棒组成。产物生长过程实验表明,首先形成球状团聚产物,然后一些颗粒在表面生长,由于奥斯瓦尔德熟化效应产物尺寸变大,最后表面上的部分颗粒消耗内部的核而外延生成一维纳米棒。CePO4∶Tb核壳微球的荧光性质和荧光寿命测试表明,当Tb3+摩尔分数为10%时,发射强度达到最大值,Tb3+浓度再增加其荧光发射强度由于浓度淬灭作用而迅速降低。

Tb3＋-doped CePO4 core-shell microspheres with diameter of 2-3 μm were hydrothermally synthesized at pH = 1.0 without using any template or surfaetant. 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 mierospheres 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.