School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, China.
Dalton Trans. 2012 Nov 7;41(41):12697-703. doi: 10.1039/c2dt31376f.
The micro/nano-structured CaWO(4)/Bi(2)WO(6) composite was successfully synthesized by a one-step hydrothermal route without using any templates or surfactants. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetry-differential scanning calorimetry (TG-DSC) and Brunauer-Emmet-Teller (BET) theory. The results indicated that the composite has a two-phase composition: CaWO(4) and Bi(2)WO(6). The photocatalytic activities of the CaWO(4)/Bi(2)WO(6) composite were evaluated for the degradation of Rhodamine B (RhB) dye and 4-nitrophenol (4-NP) in aqueous solution under visible-light irradiation (>420 nm), which were 4.5 times and 2.5 times higher than that of the pure Bi(2)WO(6), respectively. On the basis of the calculated energy band positions, the mechanism of enhanced photocatalytic activity for the micro/nano-structured CaWO(4)/Bi(2)WO(6) composite can be attributed to the effective separation of electron-hole pairs.
采用一步水热法，无需使用任何模板或表面活性剂，成功合成了具有微纳结构的 CaWO(4)/Bi(2)WO(6)复合材料。通过 X 射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、紫外-可见漫反射光谱（UV-vis DRS）、傅里叶变换红外（FT-IR）光谱、热重-差示扫描量热法（TG-DSC）和 Brunauer-Emmett-Teller（BET）理论对所制备的样品进行了表征。结果表明，该复合材料具有两相组成：CaWO(4)和 Bi(2)WO(6)。在可见光（>420nm）照射下，评估了 CaWO(4)/Bi(2)WO(6)复合材料对罗丹明 B（RhB）染料和 4-硝基苯酚（4-NP）在水溶液中的光催化降解活性，分别是纯 Bi(2)WO(6)的 4.5 倍和 2.5 倍。基于计算的能带位置，微纳结构 CaWO(4)/Bi(2)WO(6)复合材料增强光催化活性的机制可归因于电子-空穴对的有效分离。
