ZnO多级纳米结构的调控及其电化学性能研究

发布时间：2018-06-20 01:57

本文选题：ZnO多级结构 + Au纳米颗粒　；参考：《西北工业大学》2015年博士论文

【摘要】：纳米材料独特和迷人的性能引发了科学家们巨大的探索动机。ZnO是多功能的半导体材料，由于具有独特的光、电性能，已经被广泛的用在许多领域，例如，纳米激光器、发光二极管、压电纳米发动机、表面声波器件、透明的导电材料和太阳能电池等。同时，由于它的生物相容性、无毒、物理和化学稳定性等，ZnO在构建化学和生物传感器上也是最有希望的材料之一。纳米材料的性能与其形貌、尺寸和结晶性密切相关，因此，通过调节纳米结构的形貌、微观尺寸等，实现对材料性能的调控，对进一步开拓材料的应用领域具有重要的意义。由低维纳米材料作为初级结构单元组装而成的多级结构由于具有特殊形貌、尺寸和层次在诸多的应用领域都显示了优化的性能，已经受到了研究者们广泛的关注。设计和制备具有特殊形貌、尺寸的多级结构微/纳米材料，并研究材料的结构与性质关系是研究多级结构纳米材料的重要方向之一。本论文以柠檬酸钠作为结构调节剂，采用简单的一步溶液法，实现了ZnO纳米材料的可控制备，提出了柠檬酸根离子对ZnO微纳米结构的控制形成机理，进而获得了三维多级结构的多孔空心ZnO微球，并实现了它们在生物传感器上的应用；最后，设计合成了具有三明治结构的三维ZnO-石墨烯纳米复合材料，，并探讨了该复合材料作为超级电容器电极材料的电化学性能，获得了较好的结果。具体内容如下：（1）以溶液过程为基础，选用柠檬酸钠为结构调节剂，控制合成了ZnO微纳米结构，采用FESEM, TEM, XRD和FT-IR等手段对产物的结构进行了表征，详细考察了柠檬酸根离子对ZnO微纳米结构形成的影响，研究结果表明，柠檬酸钠的浓度对ZnO的形貌和晶体结构有重要的影响。基于所得的实验与表征结果，我们提出了柠檬酸根离子对ZnO微纳米结构的控制形成机理。（2）在柠檬酸钠的辅助下，控制合成了由低维的ZnO纳米片组装而成的具有三维多级结构的多孔空心ZnO微球，采用FESEM, TEM, XRD和FT-IR等手段对产物的结构和形貌进行了表征,揭示了产物的形貌和晶体结构随反应时间的变化，在最佳的反应条件下，获得的多孔的ZnO空心微球的直径约为2-3μm，比表面积为117.36m2g1，平均孔体积为0.50cm3g1。基于研究结果，我们提出了多孔空心ZnO微球的形成机理。（3）构建了基于多孔空心ZnO微球的葡萄糖生物传感器。采用Au纳米颗粒（AuNPs）修饰所合成的三维ZnO多级结构，成功合成了AuNPs高密度且高度分散的Au-ZnO纳米复合材料，以Au-ZnO纳米复合材料作为基体固定葡萄糖氧化酶（GOD），构建了一个具有生物相容性的、新型的葡萄糖传感器。由于Au-ZnO纳米复合材料具有高的比表面积、良好的生物相容性以及快速的电荷转移能力，因而获得了GOD的直接的电荷转移（DET）。所构建的传感器具有抗污染性能好、敏感性高、检测限低和稳定性好的特点。（4）采用生物相容性的Au-ZnO纳米复合材料修饰玻碳电极（GCE），构建了基于多孔空心ZnO微球的多巴胺（DA）生物传感器。由于多级结构的多孔ZnO所具有的高的比表面积以及AuNPs高的催化活性，所制备的多巴胺生物传感器显示了高的灵敏性、低的检测限和宽的线性范围。（5）采用三维ZnO多级结构作为传感平台，壳聚糖（CS）作为成膜材料，制备ZnO-CS修饰电极，将AuNPs均匀分散在ZnO-CS膜上，建立新型的、无标记的DNA传感器。由于电极表面的AuNPs/ZnO-CS膜具有较大的比表面积和较好的导电性，该传感器显示了明显的信号放大和低的检测限。（6）发展了基于ZnO-石墨烯纳米复合粒子的超级电容器。采用简单的一步湿化学方法，在石墨烯表面原位形成ZnO，成功制备了具有独特的三明治结构的ZnO-石墨烯纳米复合材料，由于ZnO大的比表面积提供了更多的活性点，纳米复合粒子独特的三明治结构提供了便利的离子运输通道，因此所制备的ZnO-石墨烯纳米复合粒子是理想的超级电容器的电极材料，用作超级电容器时，获得了较好的电化学性能，所制备的超级电容器在电流密度为1Ag-1时，比电容为786F g1，循环500圈后，电容保持率在92%以上。
[Abstract]:The unique and fascinating properties of nanomaterials have triggered the great exploration motivation of scientists,.ZnO is a versatile semiconductor material. Due to its unique light and electrical properties, it has been widely used in many fields, such as nanowire, light emitting diode, piezoelectric nano generator, surface acoustic wave device, transparent conductive material and solar energy. At the same time, because of its biocompatibility, non-toxic, physical and chemical stability, ZnO is one of the most promising materials in the construction of chemical and biological sensors. The properties of nanomaterials are closely related to their morphology, size and crystallinity. Therefore, the properties of the materials are achieved by adjusting the morphology and microsize of the nanometers. Regulation is of great significance to the further development of material applications. The multilevel structures, composed of low dimensional nanomaterials as primary structural units, have shown the optimal performance in many applications due to their special morphology, size and level, which have been widely concerned by researchers. The multi structure micro / nano material and the study of the relationship between the structure and properties of the material are one of the important directions to study the structure and properties of the multi-stage structure. This paper uses sodium citrate as a structural regulator and a simple one step solution method to realize the controllable preparation of ZnO nanomaterials. The citrate ion to ZnO microsatellite is put forward. The formation mechanism of the structure of rice is controlled, and then the porous hollow ZnO microspheres with three-dimensional multistage structure are obtained, and their application on the biosensor is realized. Finally, a three-dimensional ZnO- graphene nanocomposite with sandwich structure is designed and synthesized, and the electrochemical properties of the composite as the electrode material of the supercapacitor are discussed. Good results can be obtained. The details are as follows:
(1) based on the solution process and using sodium citrate as a structural regulator, ZnO micro nanostructures were synthesized. The structure of the products was characterized by FESEM, TEM, XRD and FT-IR. The effects of citrate ions on the formation of ZnO micro nanostructures were investigated in detail. The results showed that the concentration of sodium citrate on the morphology of ZnO and the morphology of the ZnO. Based on the experimental and characterization results, we proposed the formation mechanism of citrate ions controlling the microstructure of ZnO.
(2) under the assistance of sodium citrate, a porous hollow ZnO microsphere composed of low dimensional ZnO nanoscale was synthesized. The structure and morphology of the products were characterized by means of FESEM, TEM, XRD and FT-IR. The morphology and crystal structure of the products were revealed with the change of reaction time, and the best reaction was made. Under the conditions, the diameter of the porous ZnO hollow microspheres is about 2-3 mu m, the specific surface area is 117.36m2g1, and the average pore volume is 0.50cm3g1. based on the results of the study. We put forward the formation mechanism of porous hollow ZnO microspheres.
(3) a glucose biosensor based on porous hollow ZnO microspheres was constructed. A three-dimensional ZnO multistage structure modified by Au nanoparticles (AuNPs) was used to synthesize a AuNPs high density and highly dispersed Au-ZnO nanocomposite. A Au-ZnO nanocomposite was used as a substrate to immobilize glucose oxidase (GOD). Due to the high specific surface area, good biocompatibility and fast charge transfer ability of Au-ZnO nanocomposites, the direct charge transfer (DET) of GOD is obtained. The sensor has the advantages of good pollution resistance, high sensitivity, low detection limit and good stability. Point.
(4) a biocompatible Au-ZnO nanocomposite modified glassy carbon electrode (GCE) was used to construct a dopamine (DA) biosensor based on porous hollow ZnO microspheres. Due to the high specific surface area and high AuNPs catalytic activity of multistage porous ZnO, the prepared dopamine biosensor showed high sensitivity and low sensitivity. The detection limit and the wide linear range.
(5) the three-dimensional ZnO multistage structure is used as the sensing platform, and the chitosan (CS) is used as a film forming material to prepare the ZnO-CS modified electrode, and the AuNPs is evenly distributed on the ZnO-CS membrane, and a new and unmarked DNA sensor is established. The sensor shows obvious specific surface area and good conductivity because of the AuNPs/ZnO-CS film on the surface of the electrode. Signal amplification and low detection limit.
(6) a supercapacitor based on ZnO- graphene nanocomposite particles is developed. A simple one step wet chemical method is used to form a ZnO in situ on the surface of graphene. A unique sandwich structure of ZnO- graphene nanocomposite has been successfully prepared. Because of the specific surface product of ZnO, more active points are provided, and the nanocomposite particles are unique. The sandwich structure provides a convenient ion transport channel. Therefore, the prepared ZnO- graphene nanocomposite particles are the ideal electrode materials for the supercapacitor. When used as supercapacitors, the prepared supercapacitor has achieved good electrochemical performance. The prepared supercapacitor, when the current density is 1Ag-1, is 786F G1, and after 500 cycles of cycle, electricity is used. The retention rate is above 92%.
【学位授予单位】：西北工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB383.1;O614.241

【共引文献】