By employing KBF4 or K2SiF6 as fluoride source,a facile glycine-assisted hydrothermal route has been developed to synthesize a series of well-dispersed CaF2:Ln3+(Ln=Eu,Tb) microcrystals with a variety of morphologies,such as cubes,hollow polyhedra and hollow spheres.X-ray diffraction (XRD),Fourier transform IR (FTIR),scanning electron microscopy (SEM) and photoluminescence (PL) were used to characterize the purity,crystalline phase,morphologies and the photoluminescence properties of the samples.The XRD results show that all the as-prepared CaF2 have cubic structure and high crystallinity.The SEM results indicate that,in the presence of glycine,the as-prepared CaF2 microcrystals present morphologies of highly dispersed hollow polyhedra and hollow spheres obtained from KBF4 and K2SiF6,respectively.Meanwhile,the CaF2 hollow spheres were assembled from numerous nanocubes.In the synthetic process,glycine,fluoride source and reaction time play crucial role in confining the growth of the different morphological CaF2 microcrystals.The growth mechanism for products with diverse microstructures have been proposed based on the experimental results.%以KBF4和K2SiF6作为氟源,采用简单的甘氨酸辅助水热法制得了一系列具有不同形貌的CaF2:Ln3+(Ln =Eu,Tb)微米晶,如立方体、空心多面体和空心球.由XRD、FTIR、SEM及PL对产物的纯度、晶相、形貌和荧光性质进行了表征.XRD结果显示所有产物均为结晶良好的立方相CaF2.SEM结果表明,在添加甘氨酸的情况下,由KBF4得到的产物为空心多面体结构,而由K2SiF6制得的产物是由许多纳米块自组装成的空心球.研究发现甘氨酸、氟源种类、时间等反应参数在不同形貌CaF2:Ln3+(Ln=Eu,Tb)的形成过程中发挥关键作用,并提出了可能的反应机理.
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