CePO4纳米线的热稳定性及光学性能

以铈盐和磷酸为前驱体, 经水热合成获得了高长径比的具有六方晶型和单斜晶型独居石结构的CePO4纳米线, 采用XRD、HRTEM、SEM和荧光光度计对其晶相组成、形貌及发光性能进行了表征. 结果表明, 六方晶型CePO4纳米线直径约为40 nm, 长度约为3 μm; 单斜晶型独居石结构CePO4纳米线直径约为50 nm, 长度可达10 μm, 产物均为高纯且结晶良好的CePO4晶体. 可通过控制水热反应时间达到控制CePO4纳米线晶型的目的. 随水热反应时间的延长, 磷酸铈纳米线从六方晶型转变为单斜晶型(独居石结构). 随煅烧温度的升高, 磷酸铈纳米线直径增大, 但经1000 ℃煅烧仍具有一维线性结构, 其热稳定性高. 磷酸铈纳米线在紫外光激发下具有可见光区蓝紫发射区, 但随煅烧温度的升高, 磷酸铈纳米线的发光强度明显降低.

Thermal Stability and Optical Performance of CePO_4 Nanowires

The hexagonal and monoclinic monazite CePO4 nanowires with a narrow range of diameter distribution and large aspect ratio were synthesized mildly through hydrothermal process at 150 ℃ using CeCl3·7H2O and H3PO4 as the raw materials. The crystal structure, micro-morphology, and photoluminescence of the nanowires were characterized by XRD, TEM, HRTEM, and UV spectrophotometer. The results indicate that the diameter of hexagonal CePO4 nanowires is approximately 40 nm, the length is 3 μm, while the diameter of monoclinic(monazite) CePO4 nanowires is approximately 50 nm, the length can reach 20 μm and the nanowires are of high purity, homogeneity and well crystallinty. The crystalline phase of CePO4 nanowires can be controlled simply by changing the hydrothermal reaction time. The crystalline phase of CePO4 nanowires changes from hexagonal to monoclinic monazite while the reaction time increases. With the increase of calcining temperature, the width of CePO4 nanowires increases, and the samples remain 1D morphology even after calcined at 1000 ℃, indicating the good thermal stability of the nanowires. The intensity of UV excited emission decreases while the calcining temperature increases.