Wang Qi, Wu Hong, Gao Qiaoyuan, Lin Dagang, Fan Yongjie, Duan Ran, Cong Yanqing, Zhang Yi
School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China.
Key Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
J Colloid Interface Sci. 2019 Jul 15;548:255-264. doi: 10.1016/j.jcis.2019.04.044. Epub 2019 Apr 15.
Plasmonic Bi modified BiOI-BiO composite (Bi/BiOI-BiO) was prepared via in situ UV reduction method. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) techniques were carried out to identify the formation of semimetal Bi. The results indicated that the dot-like bismuth particles were originated from the partial reduction of lattice Bi to Bi by accumulated conduction band electrons in BiOI-BiO. The as-prepared ternary composite exhibited enhanced visible-light-response, decreased charge transfer impedance and higher charge carrier density relative to unmodified BiOI-BiO. Due to synergistic effect between plasmonic Bi and BiOI-BiO heterojunction, dramatically enhanced photocatalytic activity for phenol degradation can be achieved. After 3.5 h visible light irradiation, the value for phenol removal efficiency was ca. 60% and 100% on BiOI-BiO and Bi/BiOI-BiO, respectively. The calculated zero-order rate constant on Bi/BiOI-BiO was 1.7 and 3.9 times that on BiOI-BiO and BiO, respectively. In addition to phenol, organic dyes (zwitterionic RhB, cationic MB and anionic Org II) were also used as model pollutants. Pronounced photocatalytic degradation by Bi/BiOI-BiO can be observed, further confirming the importance of Bi. Trapping experiments using different scavengers indicated that photogenerated holes were major active species during the degradation of phenol. Furthermore, good stability was also observed in 5 successive cyclic runs. This study opens a new strategy for in situ preparation of plasmonic Bi modified composite.
通过原位紫外还原法制备了等离子体Bi修饰的BiOI - BiO复合材料（Bi/BiOI - BiO）。采用X射线衍射（XRD）、X射线光电子能谱（XPS）、扫描电子显微镜（SEM）技术来确定半金属Bi的形成。结果表明，点状铋颗粒源于BiOI - BiO中积累的导带电子将晶格Bi部分还原为Bi。相对于未修饰的BiOI - BiO，所制备的三元复合材料表现出增强的可见光响应、降低的电荷转移阻抗和更高的电荷载流子密度。由于等离子体Bi与BiOI - BiO异质结之间的协同效应，可以实现对苯酚降解的显著增强的光催化活性。在3.5小时可见光照射后，BiOI - BiO和Bi/BiOI - BiO上苯酚去除效率的值分别约为60%和100%。计算得出Bi/BiOI - BiO上的零级速率常数分别是BiOI - BiO和BiO上的1.7倍和3.9倍。除了苯酚外，有机染料（两性离子RhB、阳离子MB和阴离子Org II）也用作模型污染物。可以观察到Bi/BiOI - BiO对其有明显的光催化降解作用，进一步证实了Bi的重要性。使用不同清除剂的捕获实验表明，光生空穴是苯酚降解过程中的主要活性物种。此外，在连续5次循环运行中也观察到了良好的稳定性。本研究为原位制备等离子体Bi修饰的复合材料开辟了一种新策略。
