反应溶液 pH值对 GdVO4：Tm纳米荧光粉的影响

摘要

In the research,GdVO4:Tm nanophosphors were successfully synthesized by means of hydro-thermal synthesis with polyvinyl pyrrolidone ( PVP) as surfactant through changing the pH value of the re-action solution .The phase structure ,luminescence properties and morphologies of GdVO 4:Tm were char-acterized by X-ray diffraction (XRD),photoluminescence spectroscopy (PL) and scanning electron mi-croscopy (SEM).The results showed that the phase structure of products did not change and the crystal -linity increased as pH value increasing from 4 to 12 .When pH value was close to 12 , the products pre-pared in acid solutions were not uniform in size and aggregate seriously .When pH value was equal to 10 , the nanophosphors were approximatively spherical and possess good dispersion ,the average size of nano-particles was about 45 nm.When pH value was equal to 12,the shape of nanophosphors was rod-like and polyhedron-like besides granular ,and became irregular .Luminous intensity of phosphors increased gradu-ally as the pH value increasing and reached its highest when pH value was 12 .%采用水热法，以聚乙烯吡咯烷酮（ PVP）为表面活性剂，通过改变反应溶液pH值，合成了一系列Gd-VO4：Tm蓝色纳米荧光粉。利用X射线衍射仪（XRD）、扫描电子显微镜（SEM）和荧光光谱仪（PL）对产物的相结构、形貌和发光性能进行了表征。结果表明：随着反应溶液pH值从4逐渐增加到12，产物的相结构没有发生变化，结晶度有所增加，当pH值为12时产物的结晶度最高；在酸性环境中得到的产物大小不均匀，团聚严重。 pH 值为10时，产物微观形态接近球状，颗粒平均大小为45 nm 左右，分散性好；pH 值为12时，产物形貌呈现出不规则性，除了颗粒状之外，还存在棒状和多面体块状；随着 pH值的增加，荧光粉的发光强度逐渐增加，当pH值为12时，发光强度最高。