GdPO4∶Eu3+和GdPO4∶Ce3+,Tb3+纳米晶多元醇法的合成与表征 |
Polyol-Mediated Synthesis and Characterization of GdPO4∶Eu3+ and GdPO4∶Ce3+,Tb3+ Nanocrystals |
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摘要: 首次采用多元醇的方法合成了GdPO4∶Eu3+和GdPO4∶Ce3+,Tb3+纳米晶,并利用X-射线衍射(XRD),傅立叶变换红外光谱(FTIR),透射电镜(TEM),光致发光光谱(PL)及热重和差示扫描量热分析(TG-DSC)对产物进行了表征。结果表明,产物为单斜晶系独居石结构正磷酸盐;形貌为梭形,长轴600~700 nm,短轴50~200 nm;纳米晶在水中有良好的分散性。GdPO4∶Eu3+水溶液在251 nm激发下,发射光谱以Eu3+的5D0-7F1(592 nm)磁偶极跃迁强度最大;GdPO4∶Ce3+,Tb3+纳米晶水溶液的激发光谱在240~300 nm处有一宽的吸收带,峰值位于262 nm,为Ce3+离子的4f-5d跃迁吸收,发射光谱呈现Tb3+特征绿色发射,最强峰位于544 nm。讨论了GdPO4∶Ce3+,Tb3+体系中敏化发光机理,通过光谱分析证实了存在Ce3+→Gd3+→Tb3+的能量传递过程。 |
关键词: 磷酸盐 稀土纳米晶 光致发光 多元醇法 |
基金项目: |
Abstract: GdPO4∶Eu3+ and GdPO4∶Ce3+,Tb3+ nanocrystals were synthesized via the polyol method firstly and characterized by X-ray diffraction (XRD), FTIR spectrum, transmission electron microscopy (TEM), photoluminescence (PL) and thermal gravimetric-differential scanning calorimetry (TG-DSC). The obtained nanocrystals were of pure monoclinic phase (monazite type) orthophosphate and the morphology was nanospindles with a size of 600~700 nm in long axis and 50~200 nm in short axis. The as-prepared nanocrystals could be well-dispersed in water to form a clear colloidal solution. The colloidal solution of GdPO4∶Eu3+ showed characteristic emission of Eu3+, with the magnetic-dipole transition 5D0-7F1 (592 nm) being the most prominent peak. The excitation spectrum of GdPO4∶Ce3+,Tb3+ showed a broad band ranging from 240~300 nm with a maximum at 262 nm, which was ascribed to 4f-5d transition of Ce3+,meanwhile the emission spectrum exhibited characteristic green emission of Tb3+, with the strongest peak located at 544 nm. The sensitizing luminescence mechanism of GdPO4∶Ce3+,Tb3+ was discussed and the energy transfer from Ce3+ via Gd3+ to Tb3+ ions was observed in the nanocrystals. |
Keywords: orthophosphate rare earth nanocrystals photoluminescence polyol method |
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李 锋,郭兴家,王 猛,徐淑坤,孙思玲.GdPO4∶Eu3+和GdPO4∶Ce3+,Tb3+纳米晶多元醇法的合成与表征[J].无机化学学报,2009,25(6):968-972. |
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