Synthesis Nanostructures Of Tungstate Nanomaterials By Hydrothermal Process

In this dissertation, we explore a facile and economical method to prepare tungstate nanostructures. Furthermore, the structure and the shape of samples tungstate were characterized. And the photocatalytic property and the electrochemical property of tungstate were also investigated. The work in the paper could be divided into two parts as followings:1. The preparation of hierarchical nest-like Bi₂WO₆ structures and investigation of the property of the nest-like Bi₂WO₆ samples.Bismuth tungstate hierarchical nest-like structures built by higher order nanoplate alignment have been successfully synthesized by a facile and economical method with Bi(NO₃)₃·5H₂O and Na₂WO₄·2H₂O as starting materials in the presence of polyvinyl pyrrolidone. The samples were characterized by multiple measurements of the X-ray diffraction (XRD), the field emission scanning electron microscopy (FE-SEM), the transmission electron microscopy (TEM), the high-resolution TEM (HRTEM), and X-ray photoelectron spectra (XPS). In this paper, the photocatalytic property and electrochemical property of the Bi2WO6 nanostructure were investigated. The results showed that the as-synthesized Bi2WO6 structures showed excellent photocatalytic activity under exposure to the visible light irradiation. Therefore, the preparation and properties studies of Bi2WO6 structures suggested potential future applications in photocatalysis by sunlight and electrode candidate in lithium-ion battery.2. Prepared ZnWO4 nanostructures by hydrothermal process.The different nanostructures of Zinc tungstate samples have been successfully synthesized by a facile and economical method with Zn(NO₃)₂·6H₂O or Zn(Ac)₂·2H₂O and Na₂WO₄·2H₂O as starting materials in the presence of PVP and SDBS or NH (CH₂COOH)₂. The samples were characterized by multiple measurements of the X-ray diffraction (XRD), the field emission scanning electron microscopy (FE-SEM), the transmission electron microscopy (TEM). In this paper, the photocatalytic property of the ZnWO₄ nanostructure was investigated. The results showed that the as-synthesized ZnWO₄ structures showed excellent photocatalytic activity under exposure to UV irradiation. Therefore, the preparation and properties studies of ZnWO₄ structures suggested potential future applications in photocatalysis.