Nano-phosphors YPO4:2%Sm3+ with different pH values were synthesized with hydrothermal method. The influence of pH on structure, morphology and fluorescence property of nano-phosphor was researched. The product composition, structure, morphology and luminescent properties were characterized and analyzed with X-ray diffractometry (XRD), scanning electron microscopy (SEM and EDS), infrared spectrometer (FT-IR), ultravoilet spectrometer (UV), fluorescence spectrophotometer (FL) and other instruments. The research results indicated that: the tetragonal crystal system structure of pure phase can be obtained at pH 1–5, and the mix phases of tetragonal and hexagon can be obtained at pH 7–9. The product morphology is fusiform at pH 1; spherical at pH 3–5; and bar-shaped at pH 7–9. As pH is gradually increased from 1 to 9, the fluorescence intensity of nano-phosphor is gradually decreased and then increased. The nano-phosphor with pH 1 has the maximum fluorescence intensity and fluorescence lifetime; moreover, it has better fluorescence thermal stability, and its activation energy is 0.233 eV.

中文翻译：

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pH值对纳米荧光粉YPO4:2%Sm3+及发光性能的影响

采用水热法合成了不同pH值的纳米荧光粉YPO4:2%Sm3+。研究了pH值对纳米荧光粉结构、形貌和荧光性能的影响。用X射线衍射仪（XRD）、扫描电子显微镜（SEM和EDS）、红外光谱仪（FT-IR）、紫外光谱仪（UV）、荧光分光光度计（FL）对产物的组成、结构、形貌和发光性能进行了表征和分析。 ) 和其他工具。研究结果表明：在pH 1-5时可以获得纯相的四方晶系结构，在pH 7-9时可以获得四方和六方的混合相。产品形态在 pH 1 时为梭形；pH 3-5 时呈球形；在 pH 7-9 时呈条形。随着 pH 从 1 逐渐增加到 9，纳米荧光粉的荧光强度逐渐降低然后增加。pH为1的纳米荧光粉具有最大的荧光强度和荧光寿命；此外，它具有更好的荧光热稳定性，其活化能为0.233 eV。