Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China.
Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China.
Sci Total Environ. 2020 Jun 20;722:137825. doi: 10.1016/j.scitotenv.2020.137825. Epub 2020 Mar 10.
Although the construction of clay-supported photocatalyst is a promising strategy to develop the low cost and high activity photocatalyst, only few works researched the effect of their interfaces on the photocatalytic performance. Herein, a monoclinic BiVO/sepiolite nanocomposite was fabricated as case to study the transport mechanism of photogenerated carries based on the interfaces effect. The obtained BiVO/sepiolite nanocomposites exhibited excellent visible light photocatalytic performance. The photocatalytic degradation rates of antibiotic tetracyclines (TCs) and methylene blue (MB) by the nanocomposites are 2 and 5.34 times higher than that by pure BiVO under visible light irradiation. XPS and Raman spectra confirmed the strong interfaces effect existing between BiVO and sepiolite clay. Moreover, PL and transient photocurrent response suggested that the strong interfaces effect effectively promoted the separation of photogenerated electron-hole pairs and further enhanced the photocatalytic performance. In addition, the results of trapping experiments revealed that the photo-induced holes (h) were the dominant active species in the photocatalytic mechanism. This work illuminates the photocatalytic mechanism of monoclinic BiVO/sepiolite nanocomposites and provides a novel strategy for designing the clay-supported photocatalyst for degradation of organic pollutants.
虽然粘土负载光催化剂的构建是开发低成本、高活性光催化剂的一种很有前途的策略，但仅有少数研究工作研究了它们的界面对光催化性能的影响。在此，我们以单斜 BiVO/海泡石纳米复合材料为例，研究了基于界面效应的光生载流子输运机制。所获得的 BiVO/海泡石纳米复合材料表现出优异的可见光光催化性能。在可见光照射下，纳米复合材料对抗生素四环素 (TCs) 和亚甲基蓝 (MB) 的光催化降解速率分别比纯 BiVO 提高了 2 倍和 5.34 倍。XPS 和拉曼光谱证实了 BiVO 和海泡石粘土之间存在强烈的界面效应。此外，PL 和瞬态光电流响应表明，强烈的界面效应有效地促进了光生电子-空穴对的分离，进一步提高了光催化性能。此外，捕获实验的结果表明，光诱导空穴 (h) 是光催化机制中的主要活性物种。这项工作阐明了单斜 BiVO/海泡石纳米复合材料的光催化机制，并为设计用于降解有机污染物的粘土负载光催化剂提供了一种新策略。
