Abstract:
Photocatalysis is a prominent alternative wastewater treatment technique that has the potential to completely degrade pesticides as well as other persistent organic pollutants, leading to detoxification of wastewater and thus paving the way for its efficient reuse. In addition to the more conventional photocatalysts (e.g., TiO2, ZnO, etc.) that utilize only UV light for activation, the interest of the scientific community has recently focused on the development and application of visible light-activated photocatalysts like g-C3N4. However, some disadvantages of g-C3N4, such as the high recombination rate of photogenerated charges, limit its utility. In this light, the present study focuses on the synthesis of WO3 fibers/g-C3N4 Z-scheme heterojunctions to improve the efficiency of g-C3N4 towards the photocatalytic removal of the widely used insecticide clothianidin. The effect of two different g-C3N4 precursors (urea and thiourea) and of WO3 fiber content on the properties of the synthesized composite materials was also investigated. All aforementioned materials were characterized by a number of techniques (XRD, SEM-EDS, ATR-FTIR, Raman spectroscopy, DRS, etc.). According to the results, mixing 6.5% W/W WO3 fibers with either urea or thiourea derived g-C3N4 significantly increased the photocatalytic activity of the resulting composites compared to the precursor materials. In order to further elucidate the effect of the most efficient composite photocatalyst in the degradation of clothianidin, the generated transformation products were tentatively identified through UHPLC tandem high-resolution mass spectroscopy. Finally, the detoxification effect of the most efficient process was also assessed by combining the results of an in-vitro methodology and the predictions of two in-silico tools.
摘要:
光催化是一种突出的替代废水处理技术,具有完全降解农药以及其他持久性有机污染物的潜力,导致废水解毒,从而为其有效再利用铺平了道路。除了更常规的光催化剂(例如,TiO2,ZnO,等。)仅利用紫外线进行激活,科学界的兴趣最近集中在开发和应用可见光激活的光催化剂,如g-C3N4。然而,g-C3N4的一些缺点,例如光生电荷的高复合率,限制其效用。在这种情况下,本研究着重于WO3纤维/g-C3N4Z方案异质结的合成,以提高g-C3N4对光催化去除广泛使用的杀虫剂噻虫胺的效率。还研究了两种不同的g-C3N4前体(尿素和硫脲)和WO3纤维含量对合成复合材料性能的影响。所有上述材料均通过多种技术(XRD,SEM-EDS,ATR-FTIR,拉曼光谱,DRS,等。).根据结果,与前体材料相比,将6.5%W/WWO3纤维与脲或硫脲衍生的g-C3N4混合显着提高了所得复合材料的光催化活性。为了进一步阐明最有效的复合光催化剂在clothianidin降解中的作用,生成的转化产物通过UHPLC串联高分辨率质谱进行初步鉴定。最后,还通过结合体外方法的结果和两种计算机工具的预测来评估最有效过程的解毒效果。