【作者】 陈鹏；

【导师】 崔康平； 王淦；

【作者基本信息】 合肥工业大学 ， 环境工程（专业学位）， 2020， 硕士

【摘要】 氟喹诺酮类抗生素作为一类应用广泛的抗生素在全世界范围内受到了人们越来越多的关注,诺氟沙星抗生素作为其中的最具有代表性的抗生素,因其药效好、见效快和副作用小等优点更是受到广泛应用,但大量的使用造成诺氟沙星污染问题日渐严重。截止到目前为止,被应用于高效降解水环境污染中诺氟沙星抗生素残留和积累的各种方法已经被广泛深入研究。在这些技术当中,高级氧化技术（AOPs）凭借其处理技术简单、降解效果优异、可重复批量性和无选择性氧化等优势而在环境污染治理领域被大量研究和应用。具有和石墨烯相似的层状二维结构的黑磷（black phosphorus,BP）自2014年以来被首次人工剥离成功到现在,引发了全世界对其的爆炸性关注和研究。作为红磷和白磷之外的磷单质元素的另外一种同素异构体,BP同时也是三者之中最稳定的一种异构体形态。BP之所以能够引起如此大的关注是因为其具有很高的载流体电子迁移率,最高可达10⁴cm²/（V s）。同时另一个重要的原因是其具有石墨烯等所不具有的可调带隙结构使其在光催化材料领域拥有着无比巨大的潜力。BP虽然具有发展成为最有前景的光催化材料的潜力,但是BP也存在一些明显的缺陷,例如稳定性能一般、易氧化、和技术发展不成熟等缺点。而纳米银（Ag NPs）和聚乙二醇（PEG）作为金属离子沉积和表面修饰剂中应用比较成熟的代表能够很好地对BP的不足进行弥补。因此,通过分别将Ag NPs和PEG作为复合材料负载到BP表面,可以有效提高BP的稳定性,使其不被轻易氧化,同时能够促进BP表面发生光生载流子分离,从而可以提高其光活性。本研究研发设计两种复合光催化材料,以提升BP的稳定性和催化性能,用于对废水中诺氟沙星抗生素的降解去除。本文首先成功合成了两种新型的纳米复合材料,分别为Ag NPs@BP和PEG@BP。通过原子力显微镜（AFM）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）和X射线衍射（XRD）对两种复合材料的结构特征、微观组成和表面形态进行了广泛的研究。研究了影响诺氟沙星降解效率的关键因素,包括光照条件、p H值、催化剂类型、反应温度、催化剂用量和诺氟沙星初始浓度。基于诺氟沙星抗生素在近红外光下的光诱导降解,研究了两种复合材料的光催化降解的能力和影响因素分析。实验结果,在最佳条件下,约85.0%的诺氟沙星可被Ag NPs@BP在90 min内迅速降解,可以轻松重复使用5个循环,而不会显著降低催化活性;约64.2%的诺氟沙星可被PEG@BP在90 min内迅速降解,但其可重复性能要明显低于Ag NPs@BP。在此情况下,我们选择效果更加明显的Ag NPs@BP进行了更深入的机理探究。通过自由基淬灭实验,监测反应中产生的·O₂^-提出了光催化机理。Ag NPs@BP纳米复合材料增强的光催化活性归因于通过充分收集近红外光和高电子-空穴分离效率使BP纳米片敏化产生·O₂^-自由基降解诺氟沙星污染物。这项研究拓宽了BP的应用范围,并突出了其在处理环境污染方面的前景。更多还原

【Abstract】 As a class of widely used antibiotics,fluoroquinolone antibiotics have received more and more attention around the world.Norfloxacin antibiotics are the most representative antibiotics among them because of their good efficacy,quick results and The advantages such as small side effects have received widespread attention worldwide.A large amount of use has caused the problem of norfloxacin pollution to become increasingly serious.So far,various methods that have been applied to efficiently degrade norfloxacin antibiotic residues and accumulation in water environment pollution have been extensively and deeply studied.Among these technologies,advanced oxidation technology（AOPs）has been extensively researched and applied in the field of environmental pollution control due to its advantages of simple treatment technology,excellent degradation effect,repeatable batch and non-selective oxidation.Black phosphorus（BP）,which has a layered two-dimensional structure similar to graphene,has been successfully stripped manually for the first time since 2014 and has now caused explosive worldwide attention and research.As another isomer of phosphorus elemental elements other than red phosphorus and white phosphorus,BP is also the most stable isomer form among the three.The reason why BP can attract such great attention is that it has a high carrier fluid electron mobility,which can reach 10⁴cm²/（V s）.At the same time,another important reason is that it has an adjustable band gap structure that graphene does not have,which makes it have enormous potential in the field of photocatalytic materials.Although BP has the potential to develop into the most promising photocatalytic material,BP also has some obvious defects,such as shortcomings such as general stability,easy oxidation,and immature technological development.The nano silver（Ag NPs）and polyethylene glycol（PEG）as metal ion deposition and surface modifiers are more mature representatives can well compensate for the shortcomings of BP.Therefore,by separately loading Ag NPs and PEG as composite materials on the surface of BP,the stability of BP can be effectively improved so that it is not easily oxidized,and at the same time,the photo-generated carrier separation on the surface of BP can be promoted,so that its photoactivity can be improved.In this study,two composite photocatalytic materials were developed and designed to improve the stability and catalytic performance of BP,and used for the degradation and removal of norfloxacin antibiotics in wastewater.This paper first successfully synthesized two new types of nanocomposites,Ag NPs@BP and PEG@BP.Atomic force microscopy（AFM）,transmission electron microscopy（TEM）,scanning electron microscopy（SEM）,and X-ray diffraction（XRD）have been extensively studied on the structural characteristics,microscopic composition,and surface morphology of the two composite materials.The key factors affecting the degradation efficiency of norfloxacin were studied,including light conditions,p H,catalyst type,reaction temperature,catalyst dosage and initial concentration of norfloxacin.Based on the light-induced degradation of norfloxacin antibiotics under near-infrared light,the photocatalytic degradation capabilities and influencing factors of the two composite materials were studied.Experimental results,under the best conditions,about 85.0%of norfloxacin can be rapidly degraded by Ag NPs@BP within 90 min,and can be easily reused for 5 cycles without significantly reducing the catalytic activity;Norfloxacin can be rapidly degraded by PEG@BP within 90 minutes,but its reproducibility is significantly lower than Ag NPs@BP.In this case,we chose Ag NPs@BP with more obvious effects to conduct a more in-depth mechanism exploration.Through the free radical quenching experiment,monitoring the O₂produced in the reaction proposed a photocatalytic mechanism.The enhanced photocatalytic activity of Ag NPs@BP nanocomposites is attributed to the sensitization of BP nanosheets by full collection of near-infrared light and high electron-hole separation efficiency.·O₂^-free radicals degrade norfloxacin pollutants.This research broadens the scope of BP applications and highlights its prospects in dealing with environmental pollution.更多还原