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以Bi(NO3)3.5H2O和Na2WO4.2H2O为原料,采用水热法合成了Bi2WO6微晶。采用X射线衍射、场发射扫描电子显微镜、透射电子显微镜和紫外–可见漫反射光谱研究n(W)/n(Bi)摩尔比对合成Bi2WO6粉体的形貌和光学性能的影响。结果表明:不同的n(W)/n(Bi)比对水热法合成Bi2WO6微晶有很大影响;在n(W)/n(Bi)=0.5:1.0～2:2范围内均可制备出斜方晶系钨铋矿型结构的Bi2WO6微晶。当n(W)/n(Bi)=1:2时,Bi2WO6的结晶性能最好;随n(W)/n(Bi)比增加,Bi2WO6的形貌由卡片状球形结构向致密球形结构转变。光学性质研究表明,所制备的微晶表现出较强的紫外吸收特性,随n(W)/n(Bi)比增加,其带隙呈现减小的趋势,当n(W)/n(Bi)=1.5:2.0时所得样品的带隙最小,为2.58 eV。
Bi2WO6 crystallites were synthesized by hydrothermal method using Bi (NO3) 3.5H2O and Na2WO4.2H2O as raw materials. The effects of n (W) / n (Bi) molar ratio on the morphology and optical properties of Bi2WO6 powders were investigated by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy and UV-vis diffuse reflectance spectroscopy. The results show that the different n (W) / n (Bi) ratios have great influence on the hydrothermal synthesis of Bi2WO6 crystallites. Both n (W) / n (Bi) = 0.5: 1.0 ~ 2: 2 Preparation of orthorhombic tungsten bismuth ore type Bi2WO6 crystallite structure. The crystallinity of Bi2WO6 is the best when n (W) / n (Bi) = 1: 2. The morphology of Bi2WO6 changes from a card-shaped spherical structure to a dense spherical structure as n (W) / n . The optical properties of the prepared microcrystals showed that the prepared microcrystals exhibited strong UV absorption characteristics. With the increase of n (W) / n (Bi) ratio, the band gap showed a decreasing trend. When n (W) / n ) = 1.5: 2.0, the band gap of the resulting sample is the smallest at 2.58 eV.