Monodispersed self-assembled Eu³⁺-doped yttrium orthovanadate (YVO₄) microspheres have been prepared by a facile hydrothermal method using trisodium citrate (Na₃C₆H₅O₇) as surfactants and complexing agents. Then the as-prepared YVO₄:Eu³⁺ microspheres were subjected to the calcination treatment at different temperatures. The phase structure, microstructure, and optical properties of these microspheres were characterized by X-ray diffraction (XRD) and refinement analysis with GSAS-II, scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectra, UV–Vis reflectance spectrum (UV–Vis RS), and photoluminescence (PL) spectra, respectively. XRD revealed a pure tetragonal phase structure without any impurities of the as-prepared YVO₄:Eu³⁺ microspheres. SEM images indicated that the self-assembled YVO₄:Eu³⁺ architectures were made up of microspheres with the average diameter of around 300 nm, which were self-assembled from tiny packed nanocrystallites with 24–30 nm in diameter. Remarkably, the microstructure of these self-assembled microspheres could be well preserved during the calcination process at high temperatures. Under UV light irradiation, YVO₄:Eu³⁺ microspheres exhibited a bright red emission corresponding to the ⁵D₁→⁷F₁ and ⁵D₀→⁷F_J (J = 1, 2, 3, 4) transitions of the Eu³⁺ ions. More importantly, compared with the as-prepared YVO₄:Eu³⁺ microspheres, the microspheres after the calcined treatment showed superior optical properties, as indicated by higher emission intensity, longer decay lifetime, and higher quantum efficiency. The present results showed that the self-assembly synthesis combined with the calcination treatment could provide a facile route to optimize the luminescent properties of inorganic functional materials.

采用柠檬酸三钠（Na ₃ C ₆ H ₅ O ₇）作为表面活性剂和络合剂，通过简便的水热法制备了单分散的Eu ³⁺掺杂Eu ³⁺原钒酸钇（YVO ₄）微球。然后准备好的YVO ₄：Eu ³⁺微球在不同温度下进行煅烧处理。通过X射线衍射（XRD）和GSAS-II精细分析，扫描电子显微镜（SEM），傅立叶变换红外（FT-IR）光谱，UV-Vis表征了这些微球的相结构，微结构和光学性质。反射光谱（UV-Vis RS）和光致发光（PL）光谱。XRD显示纯正的四方相结构，没有所制备的YVO ₄：Eu ³⁺微球的任何杂质。SEM图像表明，自组装的YVO ₄：Eu ³⁺架构由平均直径约为300 nm的微球组成，这些微球是由直径24至30 nm的微小堆积纳米晶体自组装而成。值得注意的是，这些自组装微球的微观结构可以在高温煅烧过程中很好地保留。在紫外线照射下，YVO ₄：Eu ³⁺微球表现出亮红色发射，对应于Eu的⁵ D ₁ → ⁷ F ₁和⁵ D ₀ → ⁷ F _J（J = 1，2，3，4）跃迁³⁺离子。更重要的是，与准备的YVO _4相比：Eu ³⁺微球，经煅烧处理后的微球显示出优异的光学性能，如较高的发射强度，较长的衰变寿命和较高的量子效率所表明。结果表明，自组装合成与煅烧处理相结合可以为优化无机功能材料的发光性能提供一条简便的途径。