离子液体辅助CaMoO4中空微米球的制备及光学性质研究

以1-正丁基-3-甲基咪唑溴盐离子液体(BMIM]Br)/水体系为反应介质，利用简便的液相沉淀法在室温下合成了钼酸钙(CaMoO₄)中空微球体材料。分别利用X-射线粉末衍射(XRD)、场发射扫描电子显微镜(SEM)以及透射电子显微镜(TEM)对产品的相结构及形貌进行表征，发现产品为空心结构的白钨矿型微米级球体,并且该CaMoO₄微球体是由粒径为10～20 nm的纳米粒子聚集而成。利用紫外可见(UV-Vis)漫反射谱及室温光致发光(PL)谱测试了产品的光学性质。通过与纯水相、1-乙基-3-甲基咪唑溴盐离子液体(EMIM]Br)/水及1-正己基-3-甲基咪唑溴盐离子液体(HMIM]Br)/水等体系中所得产品的对比，证明了BMIM]Br对产品的形貌及光学性能等具有重要影响，并对中空微球体形成的机理进行了讨论。

CaMoO4 Hollow Microspheres: Ionic Liquid-assisted Synthesis and Optical Properties

Calcium molybdate (CaMoO₄) hollow microspheres were fabricated via a facile liquid-phase route in 1-n-butyl-3-methyl imidazolium bromide ionic liquid (BMIM]Br)/water at room temperature. The phase structure and morphology of the product were characterized by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. It was found that the product had a hollow architecture with the scheelite structure, and these microspheres were assembled by nanoparticles with a diameter ranged from 10 to 30 nm. Optical properties were investigated through UV-Visible (UV-Vis) diffuse reflectance spectroscopy, photoluminescence (PL) emission spectroscopy. The results show that the ionic liquid BMIM]Br plays an important role on the morphology and optical properties of as-prepared CaMoO₄ by comparison with those products obtained from aqueous solution, EMIM]Br/water and HMIM]Br/water system, respectively. The formation mechanism of such hollow microspheres is also discussed.