Dong Pengyu, Xi Xinguo, Zhang Xinjiang, Hou Guihua, Guan Rongfeng
Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, Yancheng Institute of Technology, Yancheng 224051, China.
Jiangsu Collaborative Innovation Center for Ecological Building Materials and Environmental Protection Equipments, Yancheng Institute of Technology, Yancheng 224051, China.
Materials (Basel). 2016 Aug 11;9(8):685. doi: 10.3390/ma9080685.
Monoclinic BiVO₄ photocatalysts with porous structures were synthesized by a two-step approach without assistance of any templates. The as-prepared samples were characterized by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy (DRS), photocurrent responses, and electrochemical impedance spectra (EIS). It is found that the as-prepared BiVO₄ samples had a porous structure with aperture diameter of 50-300 nm. Moreover, the BET specific surface area of the porous BiVO₄-200 °C sample reaches up to 5.69 m²/g, which is much higher than that of the sample of BiVO₄ particles without porous structure. Furthermore, a possible formation mechanism of BiVO₄ with porous structure was proposed. With methylene blue (MB) as a model compound, the photocatalytic oxidation of organic contaminants in aqueous solution was investigated under visible light irradiation. It is found that the porous BiVO₄-200 °C sample exhibits the best photocatalytic activity, and the photocatalytic rate constant is about three times of that of the sample of BiVO₄ particles without porous structure. In addition, the photocurrent responses and electrochemical impedance spectra strongly support this conclusion.
采用两步法在无任何模板辅助的情况下合成了具有多孔结构的单斜晶系BiVO₄光催化剂。通过X射线衍射图谱(XRD)、扫描电子显微镜(SEM)、布鲁诺尔-埃米特-泰勒(BET)法、紫外-可见(UV-vis)漫反射光谱(DRS)、光电流响应和电化学阻抗谱(EIS)对所制备的样品进行了表征。结果发现,所制备的BiVO₄样品具有孔径为50-300 nm的多孔结构。此外,多孔BiVO₄-200 °C样品的BET比表面积高达5.69 m²/g,远高于无多孔结构的BiVO₄颗粒样品。此外,还提出了具有多孔结构的BiVO₄的可能形成机理。以亚甲基蓝(MB)为模型化合物,研究了可见光照射下水溶液中有机污染物的光催化氧化。结果发现,多孔BiVO₄-200 °C样品表现出最佳的光催化活性,光催化速率常数约为无多孔结构的BiVO₄颗粒样品的三倍。此外,光电流响应和电化学阻抗谱有力地支持了这一结论。