Lin Shuanglong, Liu Li, Liang Yinghua, Cui Wenquan, Zhang Zisheng
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
College of Chemical Engineering, Hebei Key Laboratory for Environment Photocatalytic and Electrocatalytic Materials, North China University of Science and Technology, Tangshan 063009, China.
Materials (Basel). 2016 Jun 17;9(6):486. doi: 10.3390/ma9060486.
In this work, a series of novel flower-like Ag@AgCl/Bi₂O₂CO₃ were prepared by simple and feasible oil-in-water self-assembly processes. The phase structures of as-prepared samples were examined by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS), X-ray fluorescence spectrometer (XRF), . The characterization results indicated that the presence of Ag@AgCl did not affect the crystal structure, but exerted a great influence on the photocatalytic activity of Bi₂O₂CO₃ and enhanced the absorption band of pure Bi₂O₂CO₃. The photocatalytic activities of the Ag@AgCl/Bi₂O₂CO₃ samples were determined by photocatalytic degradation of methylene blue (MB) under visible light irradiation. The Ag@AgCl (10 wt %)/Bi₂O₂CO₃ composite showed the highest photocatalytic activity, degrading 97.9% MB after irradiation for 20 min, which is over 1.64 and 3.66 times faster than that of pure Ag@AgCl (calculated based on the equivalent Ag@AgCl content in Ag@AgCl (10 wt %)/Bi₂O₂CO₃) and pure Bi₂O₂CO₃, respectively. Bisphenol A (BPA) was also degraded to further prove the degradation ability of Ag@AgCl/Bi₂O₂CO₃. Photocurrent studies indicated that the recombination of photo-generated electron-hole pairs was decreased effectively due to the formation of heterojunctions between flower-like Bi₂O₂CO₃ and Ag@AgCl nanoparticles. Trapping experiments indicated that O₂, h⁺ and Cl° acted as the main reactive species for MB degradation in the present photocatalytic system. Furthermore, the cycling experiments revealed the good stability of Ag@AgCl/Bi₂O₂CO₃ composites. Based on the above, a photocatalytic mechanism for the degradation of organic compounds over Ag@AgCl/Bi₂O₂CO₃ was proposed.
在本工作中，通过简单可行的水包油自组装工艺制备了一系列新型花状Ag@AgCl/Bi₂O₂CO₃。采用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（DRS）、X射线荧光光谱仪（XRF）对所制备样品的相结构进行了检测。表征结果表明，Ag@AgCl的存在不影响晶体结构，但对Bi₂O₂CO₃的光催化活性有很大影响，并增强了纯Bi₂O₂CO₃的吸收带。通过在可见光照射下光催化降解亚甲基蓝（MB）来测定Ag@AgCl/Bi₂O₂CO₃样品的光催化活性。Ag@AgCl（10 wt%）/Bi₂O₂CO₃复合材料表现出最高的光催化活性，光照20分钟后降解97.9%的MB，分别比纯Ag@AgCl（基于Ag@AgCl（10 wt%）/Bi₂O₂CO₃中等效Ag@AgCl含量计算）和纯Bi₂O₂CO₃快1.64倍和3.66倍。还对双酚A（BPA）进行了降解，以进一步证明Ag@AgCl/Bi₂O₂CO₃的降解能力。光电流研究表明，由于花状Bi₂O₂CO₃与Ag@AgCl纳米颗粒之间形成异质结，光生电子 - 空穴对的复合有效地减少。捕获实验表明，O₂、h⁺和Cl°是当前光催化体系中MB降解的主要活性物种。此外，循环实验揭示了Ag@AgCl/Bi₂O₂CO₃复合材料具有良好的稳定性。基于以上结果，提出了Ag@AgCl/Bi₂O₂CO₃上有机化合物降解的光催化机理。
