不同晶型磷酸铈纳米材料的水热法合成及荧光性能  

Hydrothermal Synthesis and Fluorescence Properties of Cerium Phosphate Nanomaterials with Different Crystal Structures

作　　者：杨丽格[1] 周泊[1] 陆天虹[1] 蔡称心[1] 

机构地区：[1]南京师范大学化学与环境科学学院,江苏省生物功能材料重点实验室,南京210097

出　　处：《应用化学》2008年第6期697-701,共5页Chinese Journal of Applied Chemistry

基　　金：国家自然科学基金(20373027,20673057,20773065);“新世纪优秀人才支持计划”(NET-06-0508);江苏省自然科学基金(BK2005138);江苏省高校自然科学基金(06KJB150061)资助项目

摘　　要：利用水热法成功地合成了不同晶型结构和形状的CePO4纳米发光材料。采用XRD、TEM、SEM及荧光光谱等测试技术对所制备的样品进行了表征，并探讨了溶液pH值、反应温度等因素对其晶型结构、形貌及荧光性能的影响。结果表明，在酸性溶液中（pH=1）制备的CePO4呈现纳米棒状并具有很好的结晶度，而在碱性溶液中（pH=12）制备的样品则为球状的纳米颗粒，结晶度较低。CePO4纳米材料的晶型结构也受制备温度的影响，在溶液pH=1时，120℃下制备的样品具有六方晶型；随着反应温度的升高，逐渐有单斜晶型的产物生成，当温度达200℃时，制备的样品为纯单斜晶型。荧光光谱的分析结果表明，各种条件下所制备的CePO4纳米材料均在300～400nm之间有强的发射谱带，但单斜晶型CePO4的荧光强度要远大于六方晶型的荧光强度。CePO4 fluorescence nanomaterials with different crystal structures and morphology was hydrothermally synthesized and characterized with the techniques of X-ray diffraction （XRD）, transmission electron microscopy（TEM）, scanning electron microscopy （SEM） and fluorescence spectroscopy, etc. The effects of pH and temperature on the crystal structure, morphology and fluorescent intensity of CePO4 were investigated. The SEM results indicated that CePO4 prepared in acidic solution （pH = 1, 120 ℃ ） were nanorods, while CePO4 prepared in alkaline solution （pH = 12, 120 ℃） were nanoparticles. The XRD results showed that CePO4 prepared in acidic（pH = 1, 120℃） solution had a hexagonal crystal structure. However, the crystallinity of CePO4 obtained in the acidic solution was better than that of CePO4 obtained in the alkaline solution. The crystal structure of CePO4 depended on the preparation temperature. The CePO4 had a hexagonal crystal structure when it was prepared at 120 ℃and pH = 1. CePO4 with monoclinic and hexagonal crystal structures can be simultaneously formed with increasing the preparation temperature. Only CePO4 with the monoclinic structure was obtained when the temperature was 200℃. Fluorescence spectra indicated that both hexagonal and monoclinic CePO4 showed a broad emission band at between 300 -400 nm due to the 5d- 4f emission of cerium. However, the fluorescence intensity of the monoclinic CePO4 was stronger than that of hexagonal one.

关 键 词：纳米材料 水热合成 晶体结构 荧光 CEPO4 

分 类 号：O648[理学—物理化学]