尿素均相沉淀法制备菱形Gd_2O_3:Eu^(3+)纳米荧光粒子

Preparation of Gd_2O_3:Eu^(3+) Nanophosphor with Rhombus Shape via Urea-assisted Homogeneous Precipitation Method

以尿素为沉淀剂,稀土氯化物为原料,采用均相沉淀法制备Eu^(3+)掺杂的Gd_2O(CO_3)_2·H_2O纳米粒子,经过煅烧后得到Gd_2O_3:Eu^(3+)纳米荧光粉。利用扫描电镜(SEM)对纳米粒子的形貌和粒径进行表征,采用X-射线粉末衍射(XRD)、傅立叶红外光谱仪(FT-IR)等对纳米粒子的成分进行分析,研究了回流时间对纳米粒子的形貌和粒径的影响。结果表明:在回流结晶的过程中无定形的球形Gd_2O(CO_3)_2·H_2O纳米粒子逐步转化为菱形Gd_2O(CO_3)_2·H_2O纳米晶,煅烧后转化为立方相的Gd_2O_3:Eu^(3+),且在煅烧过程中它们的氧化物继承其碳酸盐前驱体的形貌。荧光测试表明,该菱形Gd_2O_3:Eu^(3+)纳米荧光粒子在253 nm紫外光激发下,其发射主峰位于611 nm,表现出强烈的红光。

In this paper, we report the synth esis of Gd2O3：Eu3 ＋red nanophosphor via urea-assisted precipitation process followed by calcination. During the synthesis, gadolinium carbonate was used as the precursor. The properties were characterized with the powder X-ray diffraction（XRD）, scanning electron microscopy（SEM）, IR spectrum（IR） and photoluminescence（PL）. It was observed that the amorphous spherical nanoparticles has been precipitated firstly, then transformed to rhombus Gd2O（CO3）2·H2O as the reaction continues. After a calcination process, both of the amorphous spheres and crystalline rhombus Gd2O（CO3）2·H2O particles converted into crystalline Gd2O3 at 800 OC, and they inherit the original shape of the precursors. The PL analysis exhibited the Gd2O3：Eu3 ＋nanophosphor emit orange-red Luminescence light due to the 5D0→7F2 transition of the Eu3＋ions under UV excitation of 253 nm.