纳米CeO2/多孔石墨烯催化增敏及多种电子垃圾污染物同时检测新方法研究

Cu(II), Pb(II) and TBBPA are three kinds of widely existing e-waste persistent pollutants. Since their electrochemical signals are distributed from negative potential region to positive one, there are no reports dealing with simultaneous and electrochemical detection of Cu(II), Pb(II) and TBBPA up to now. CeO2 based nanomaterials (Nano-CeO2) show high catalytic activity in the negative and positive potential regions, while they are easy to aggregate, and have a low electrical conductivity. Moreover, their catalytic activity is dependent of the exposed crystal facets. Herein，in this project the incorporation of nano-CeO2 with porous graphene is proposed with an aim to solve the problems of poor conductivity and agglomeration of nano-CeO2. In this way, the catalytic activity of nano-CeO2 will be enhanced remarkably in the required potential ranges for the simultaneous and electrochemical detection of Cu(II), Pb(II) and TBBPA. A controllable-morphology technique will be developed to alter the morphology and exposed crystal facets of nano-CeO2. Such novel materials will feature high catalytic activity, high surface area, and abundant acting sites. They are thus employed as the sensing materials. In the course of this project, we will investigate the influence of the morphology and exposed crystal facets of these nano-CeO2 on the electrochemical sensing of Cu(II), Pb(II) and TBBPA; The enhancement of electrochemical signals and the related mechanisms, the key scientific questions for the remarkable improvement of sensitivity of electrochemical detection, will be investigated and proposed. Finally, novel electrochemical methods will be developed for highly sensitive, selective and simultaneous detection of Cu (II), Pb (II), and TBBPA. These methods based electrochemical senors will be utilized for in-situ and rapid analysis of persistent pollutants. This work will provide new strategies and new devices for the rapid detection of trace amount of e-waste persistent pollutants. New idea about the development of high-performance electrochemical sensing materials will be explored as well. In summary, the success of this project is not only of great theoretical significance but also practical importance.

Cu(II)、Pb(II)和TBBPA是三种广泛存在的电子垃圾持久性污染物，三者的响应信号分布在负电位和正电位区域，其同时电化学测定未见报道。纳米CeO2在正负电位区域都表现出高催化活性，但其易团聚、导电性弱且催化活性受暴露晶面制约。为此，本项目将纳米CeO2与多孔石墨烯复合，首先解决导电性弱、易团聚难题，借此显著提高纳米CeO2的催化活性；其次通过形貌调控技术控制纳米CeO2的形貌和暴露晶面，制备出催化活性高、比表面积大、作用位点丰富的新型电化学传感材料；研究形貌和晶面对电化学传感器响应性能的影响规律，探究电化学信号增强机制，解决显著提高三者同时测定的电化学检测灵敏度等关键科学问题，建立高灵敏度、高选择性电化学新方法，研制出适合现场快速分析的电化学传感器。课题将为痕量电子垃圾持久性污染物的快速检测提供新方法和新器件，同时为高性能电化学传感材料的研制提供新思路，具有重要的理论和现实意义。

本项目将金属氧化物（CeO2、Fe2O3、CuO）与碳材料（多孔石墨烯、石墨烯纳米片、膨胀石墨）复合，并进一步调控金属氧化物的形貌和暴露晶面，详细研究了形貌和晶面对其电化学传感器响应性能的影响规律，探究了电化学信号增强机制；此外，还成功制备了MOFs及其衍生物、金属颗粒/碳等新型电化学传感材料；最终，建立了环境中电子垃圾持久性污染物（TBBPA、重金属离子等）及其它有机污染物（壬基酚等）的高灵敏度、高选择性电化学检测新方法。.项目按照研究计划，完成了预期的研究内容，实现了既定目标，主要如下：.1、通过改变水热反应条件（例如碱源的种类和浓度、反应温度和时间）成功制备出不同形貌（包括片、立方体、三角形片、束、多面体和棒）的纳米CeO2，且实现了选择性暴露晶面，为复合材料的形貌调控奠定了基础；.2、以GO为前驱体，通过AgAc刻蚀法、H2O2水热刻蚀法、微波剥离法、硬模板（ZnO、 CaO及SiO2）法合成了一系列不同孔径的二维多孔石墨烯、三维多孔石墨烯，结果显示通过改变AgAc的加入量及模板的粒径可以实现对多孔石墨烯的孔径调控，电化学实验数据表明所制备的多孔石墨烯具有较大的电活性面积和较快的电子转移速率；.3、成功制备了不同形貌CeO2/碳（石墨烯纳米片、多孔石墨烯、膨胀石墨）的复合材料，研究了酚类污染物（TBBPA等）、重金属离子（Cd(II)、Pb(II)等）的电化学信号增强规律，结果表明具有较大比表面积及暴露高活性晶面的复合材料具有较强的电化学传感性能，实现了电子垃圾污染物的高灵敏度、高选择性检测，实际样品（湖水、土壤样品、电子产品）分析结果表明所开发的电化学传感器具有高度准确性及适用性，为提高其他电极材料的传感性能提供借鉴与参考；.4、成功制备出Fe2O3/膨胀石墨、CuO/石墨烯、MOFs及其衍生物、金属纳米颗粒/碳等新型电化学传感材料，探讨了形貌与电化学传感性能之间的关系，并实现了多种分析物（TBBPA、日落黄、柠檬黄、壬基酚和苯二酚异构体等）的高灵敏检测，为新型电化学传感器的开发及应用提供了技术基础和科学依据。