Abstract A simple one-step hydrothermal strategy has been developed to fabricate Sr2YF7 hierarchical microspheres employing NH4BF4 as fluoride source. The crystalline phase and morphologies of the products were characterized by XRD, TEM and SEM. The XRD results showed that the as-prepared samples were tetragonal phased Sr2YF7 with high crystallinity. SEM and TEM observation indicated that the as-synthesized hierarchical microspheres with average size of about 2 μm were assembled by hollow polyhedrons. N2 adsorption–desorption measurements revealed that the BET specific surface area of the typical Sr2YF7 hierarchical microspheres is up to 111.4 m2/g. The size and morphology of the products could be effectively controlled by adjusting the reaction times. Furthermore, the photoluminescence of hierarchical Sr2YF7:Eu3+ microspheres and hollow polyhedrons were measured, the result showed that PL intensity and decay time were sensitive to the morphology of the product.

中文翻译：

---

Sr2YF7:Eu3+空心多面体组装分级微球的无模板合成及光致发光性能

摘要 已经开发了一种简单的一步水热策略来制造 Sr2YF7 分级微球，采用 NH4BF4 作为氟化物源。通过XRD、TEM和SEM对产物的晶相和形貌进行表征。XRD 结果表明所制备的样品是具有高结晶度的四方相 Sr2YF7。SEM 和 TEM 观察表明，所合成的平均尺寸约为 2 μm 的分级微球由空心多面体组装而成。N2 吸附-解吸测量表明，典型的 Sr2YF7 分级微球的 BET 比表面积高达 111.4 m2/g。通过调节反应时间可以有效控制产物的尺寸和形貌。此外，分级 Sr2YF7 的光致发光：