CONACyT-División de Materiales Avanzados, Instituto Potosino de Investigación Científica y Tecnológica A. C., 78216, San Luis Potosí, SLP, Mexico.
CONACyT-División de Materiales Avanzados, Instituto Potosino de Investigación Científica y Tecnológica A. C., 78216, San Luis Potosí, SLP, Mexico.
J Environ Manage. 2022 Sep 1;317:115514. doi: 10.1016/j.jenvman.2022.115514. Epub 2022 Jun 14.
In this research, we evaluated the photocatalytic performance of biodegradable composites for the removal of the 2,4-Dichlorophenoxyacetic acid (2,4-D) herbicide. The composite was composed by agave fibers (AgF), graphene-microplates (GM) and titanium dioxide TiO/SnO (TSn) nanoparticles (NPs) and was named TSn + AgF/GM. Both, the TSn NPs and the GM were deposited on the AgF using the Dip-coating method. According to the analysis by X-Ray Diffraction (XRD), the crystalline phase for the TiO and SnO was anatase and tetragonal-rutile, respectively. The Scanning Electron Microscopy (SEM) images demonstrated that the AgF were completely saturated by the GM (which had average dimensions of 15 μm × 22 μm) and by conglomerations of TSn NPs with average size of 642 nm. The TSn NPs and the TSn + AgF/GM composite were evaluated for the photocatalytic degradation of the 2,4-D herbicide under ultraviolet-visible (UV-Vis) light and found a maximum degradation of 98.4 and 93.7% (after 4 h) for the TSn NPs and the TSn + AgF/GM composite, respectively. Reuse cycles were also performed and the degradation percentage decreased by 13.1% and by 7.8% (after 3 cycles of reuse) when the TSn NPs and the TSn + AgF/GM composite are employed, respectively. Scavenger experiments were also carried out and found that the oxidizing agents are mainly produced in the order of: •OH>•O > h; then, the main oxidizing agents generated during the photocatalytic reaction were the hydroxyl radicals. Thus, the photocatalytic system studied in this work for the degradation of 2,4-D could pave the way for the development of new eco-friendly/floatable photocatalysts, which can be applied in wastewater-treatment plants.
在这项研究中，我们评估了可生物降解复合材料对 2,4-二氯苯氧乙酸（2,4-D）除草剂的光催化性能。该复合材料由龙舌兰纤维（AgF）、石墨烯微板（GM）和二氧化钛 TiO/SnO（TSn）纳米颗粒（NPs）组成，并被命名为 TSn+AgF/GM。TSn NPs 和 GM 都是通过浸渍法沉积在 AgF 上的。根据 X 射线衍射（XRD）分析，TiO 和 SnO 的晶相分别为锐钛矿和四方金红石。扫描电子显微镜（SEM）图像表明，AgF 完全被 GM（平均尺寸为 15μm×22μm）和 TSn NPs 聚集体所饱和，聚集体的平均尺寸为 642nm。TSn NPs 和 TSn+AgF/GM 复合材料在紫外可见（UV-Vis）光下用于光催化降解 2,4-D 除草剂，TSn NPs 和 TSn+AgF/GM 复合材料的最大降解率分别为 98.4%和 93.7%（4 小时后）。还进行了重复使用循环实验，当 TSn NPs 和 TSn+AgF/GM 复合材料重复使用 3 次后，降解百分比分别降低了 13.1%和 7.8%。进行了清除剂实验，发现氧化剂的产生顺序主要为：•OH＞•O＞h；然后，在光催化反应中主要产生的氧化剂是羟基自由基。因此，本工作研究的用于降解 2,4-D 的光催化体系为开发新的环保/可浮型光催化剂铺平了道路，这些光催化剂可应用于废水处理厂。
