水热合成ZnWO4粉体的结构、形貌及其发光性能

The Phase Structure, Morphology and Luminescent Properties of ZnWO4 Powders by Hydrothermal Process

摘要:

采用水热法，通过控制焙烧温度和PEG-1000用量制备了一系列不同发光强度的ZnWO4荧光粉体，运用X射线粉末衍射仪、红外光谱、扫描电子显微镜和荧光分光光度计等对样品进行了分析和表征。结果表明：得到的ZnWO4蓝色荧光粉均为黑钨矿纯相；水热产物为类球形小颗粒，经700 ℃焙烧后得边缘清晰的短棒状结构；添加0.5 g PEG-1000且700 ℃焙烧后所得样品颗粒仍为短棒状结构，但其颗粒尺寸明显减小。ZnWO4的发射光谱由一宽发射带组成，峰值位于465 nm处；水热法制备的ZnWO4粉末经过焙烧可以提高荧光粉的结晶度和发光性能，最佳焙烧温度为700 ℃；表面活性剂PEG-1000的添加也使得荧光粉的发光强度明显提高，最佳用量为0.8 g。

Abstract:

Under various calcination temperatures and with different dosage of PEG-1000, a series of ZnWO4 phosphors were synthesized by hydrothermal process. The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscope and Fluorescence spectrophotometer. The results show that as-synthesized blue-emitting phosphors ZnWO4 are pure wolframite structure. The particles of hydrothermal product are spheres in shape, and after calcination at 700 ℃, the morphology is changed from spheres to short rods. Under the condition of adding 0.5 g PEG-1000 and calcination at 700 ℃, the obtained particles are still short rods in shape, but the size is reduced significantly. The emission spectrum of ZnWO4 is composed of a broad band with the main peak at 465 nm. The crystallinity and luminescent property of the ZnWO4 powder synthesized by hydrothermal process can be improved by calcination, and the optimal calcination temperature is 700 ℃. Adding surfactant PEG-1000 can also increase the luminescent intensity of the phosphors, and the optimal dosage is 0.8 g.