氮掺杂石墨烯负载钴系金属氧化物的制备及其超级电容器电极性能研究

发布时间：2018-08-01 15:37

【摘要】：目前人类社会在能源与发展方面面临日渐尖锐的挑战,寻找一种清洁高效能源和存储能源材料的需求越发急迫。超级电容器因与普通电容器、传统电池相比在放电时间、放电电流、使用寿命以及环境保护方面更有优势而备受关注。在各种金属氧化物中,成本更加低廉、储量更加丰富、环境更加友好、毒害更加轻微的四氧化三钴及钴酸镍成为了研究的重点。然而金属氧化物导电能力差、易团聚、与电解液接触界面面积小等不足制约着其在电容器实际应用方面的前景。石墨烯是碳原子以sp2杂化排列形成的一种二维蜂窝状碳材料,具有更高的强度、极佳的导电性以及超大的比表面积。石墨烯具有极佳的化学稳定性并且在力学、光学、热力学、电化学等领域应用前景广阔。研究者为了进一步研究和发掘石墨烯的潜能在其表面进行掺杂引入异种元素以此来合成新的石墨烯基材料。氮掺杂石墨烯在保持石墨烯原有结构的前提下能够修复部分石墨烯的结构缺陷,从而增加石墨烯表面的活性位点,增强石墨烯的储电能力。将金属氧化物与氮掺杂石墨烯复合不仅可以发挥各自的性能优势,还可以产生电子转移协同效应,进一步增强复合材料的电容器性质。所以研发出性能可靠的超级电容器材料具有重要的研究意义和实用价值。本文的主要内容如下:1.以聚丙烯酰胺(PAM)为表面活性剂,通过微波-煅烧法制备得到Co_3O_4纳米粒子氮掺杂石墨烯复合物。利用XRD、FTIR、Raman、TEM、XPS、ICP、电化学工作站测试等方法对Co_3O_4/NG复合物的结构、形貌和电化学性能进行表征。实验结果表明,在950 W功率下微波加热15 min后将产物在750℃下煅烧3 h,Co_3O_4纳米粒子能够均匀的分散在氮掺杂石墨烯表面,在1 A g-1的电流密度下测得的比电容为1288.2 F g-1。Co_3O_4/NG复合物优良的电化学活性主要归因于Co_3O_4纳米颗粒与氮掺杂石墨烯之间的协同作用。2.以六亚甲基四胺(HMT)、尿素(Urea)为碱源,通过水热-煅烧法制备的到NiCo_2O_4纳米管氮掺杂石墨烯复合物。利用XRD、TGA、FTIR、Raman、TEM、XPS、ICP、电化学工作站测试等方法对NiCo_2O_4/NG复合物的结构、形貌和电化学性能进行表征。实验结果表明,以六亚甲基四胺作为碱源,在180℃下水热24 h后将产物在350℃下煅烧3 h,形成管径均一的NiCo_2O_4晶体沉积在氮掺杂石墨烯表面,在1 A g-1的电流密度下测得的比电容为2147.4 F g-1。NiCo_2O_4/NG复合物出色的电容性能归因于NiCo_2O_4纳米管与氮掺杂石墨烯活性位点之间的协同效应,还得益于三维空间介孔结构的NiCo_2O_4纳米管晶体能够极大的增加金属氧化物与电解液的接触面积,从而展现出更加优良的电容性能。3.以六亚甲基四胺作为碱源、聚丙烯酰胺作为表面活性剂,通过水热-煅烧法制备得到双金属复合的Co_3O_4@NiCo_2O_4纳米粒子氮掺杂石墨烯复合物。通过XRD、Raman、FTIR、ICP、TEM、XPS、电化学测试等方法对Co_3O_4@NiCo_2O_4/NG复合物的形貌结构以及电化学性能进行表征。实验结果表明,适量的六亚甲基四胺和少量的聚丙烯酰胺表面活性剂有利于三明治形状的双金属氮掺杂石墨烯复合物,在180℃下水热24 h后将产物在350℃下煅烧3 h,形成片状的NiCo_2O_4晶体表面生长有Co_3O_4纳米颗粒并与氮掺杂石墨烯复合形成三明治状的空间结构,在1 A g-1的电流密度下测得的比电容为2387.5 F g-1。Co_3O_4@NiCo_2O_4/NG复合物的卓越性能得益于三明治状的特殊三维空间结构和金属氧化物与氮掺杂石墨烯间的进一步电子协同作用。
[Abstract]:At present, human society is facing an increasingly acute challenge in energy and development. It is more and more urgent to find a clean and efficient energy and energy storage material. Supercapacitor is concerned about the advantages of discharge time, discharge current, service life and environmental protection compared with conventional capacitors and traditional batteries. In the metal oxides, the cost is lower, the reserves are more abundant, the environment is more friendly, and the toxicity of the four oxidation of cobalt and nickel cobalt oxide is the focus of the study. However, the poor conductivity of the metal oxide, the easy reunion and the small contact interface with the electrolyte restrict its application in the practical application of the capacitor. A two-dimensional honeycomb carbon material formed by SP2 hybrid arrangement of carbon atoms, with higher strength, excellent conductivity and large specific surface area. Graphene has excellent chemical stability and is widely used in the fields of mechanics, optics, thermodynamics and electrochemistry. In order to further study and explore graphene The potential on its surface is doped with heterologous elements to synthesize new graphene based materials. Nitrogen doped graphene can repair the structural defects of some graphene on the premise of maintaining the original structure of graphene, thus increasing the active site of the graphene surface, enhancing the power storage capacity of graphene, and doping metal oxide and nitrogen. Graphene composite can not only give play to its own performance advantages, but also produce the synergistic effect of electron transfer, and further enhance the properties of the capacitor of the composite. Therefore, it is of great significance and practical value to develop a reliable supercapacitor material. The main contents of this paper are as follows: 1. the surface of polyacrylamide (PAM) is the surface. Co_3O_4 nanoparticle nitrogen doped graphene complex was prepared by microwave calcination. The structure, morphology and electrochemical properties of the Co_3O_4/NG complex were characterized by XRD, FTIR, Raman, TEM, XPS, ICP, and electrochemical workstation testing. The experimental results showed that the product was 750 after microwave heating of 15 min at 950 W power. Calcined 3 h at C, Co_3O_4 nanoparticles can be dispersed uniformly on the surface of nitrogen doped graphene. The excellent electrochemical activity of the specific capacitance of 1288.2 F g-1.Co_3O_4/NG complexes under the current density of 1 A g-1 is mainly attributed to the synergistic effect of Co_3O_4 nanoparticles and nitrogen doped graphene,.2. with six methylene four amine (HMT), and urine. XRD, TGA, FTIR, Raman, TEM, XPS, ICP, and electrochemical workstations were tested by XRD, TGA, FTIR, Raman, TEM, XPS, ICP, and electrochemical workstations. The experimental results showed that six methylene four amine was used as the base source, and 180 was used as the base source. After 24 h, the product was calcined at 350 centigrade for 3 h, and the uniform diameter of the NiCo_2O_4 crystal was deposited on the surface of nitrogen doped graphene. The excellent capacitance of the specific capacitance of 2147.4 F g-1.NiCo_2O_4/NG under the current density of 1 A g-1 was attributed to the synergy between the NiCo_2O_4 nanotubes and the active site of nitrogen doped graphene. The effect, also benefited from the NiCo_2O_4 nanotube crystal in the three-dimensional mesoporous structure, can greatly increase the contact area of the metal oxide and the electrolyte, thus showing a better capacitive performance.3. with six methylene four amine as the base source and the polyacrylamide as the surfactant to prepare the bimetallic composite by the hydrothermal calcination method. The morphology and electrochemical properties of the Co_3O_4@NiCo_2O_4/NG complex were characterized by XRD, Raman, FTIR, ICP, TEM, XPS, electrochemical testing and other methods. The results showed that a proper amount of six methylene four amines and a small amount of polyacrylamide surfactants were beneficial to three. The Meiji form of bimetallic doped graphene complex, after 24 h water heat at 180 C, calcined the product at 3 h at 350 C, formed a sheet like NiCo_2O_4 crystal with Co_3O_4 nanoparticles and formed a sandwich space structure with nitrogen doped graphene, and the specific capacitance measured at 1 A g-1 was 2387.5 F g-1.C. The excellent performance of the o_3O_4@NiCo_2O_4/NG complex is attributed to the sandwich shaped special three-dimensional space structure and the further electronic synergy between the metal oxide and the nitrogen doped graphene.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB332;TM53

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