碳纳米管包覆零价铁与四氧化三钴超级电容性能研究

发布时间：2018-03-21 03:24

  本文选题：超级电容器　切入点：碳纳米管　出处：《南昌大学》2015年硕士论文　论文类型：学位论文

【摘要】：超级电容器作为一种新型的储能器件,由于具有功率密度高、充放电速度快、循环稳定性好和环境友好等特点,在现代电源系统中有着广泛的应用并受到越来越多国内外科学家的广泛关注。其中电极材料的性质和形貌结构是影响超级电容器性能的关键因素,如何提高电极材料的电容值和制备具有优良电容性能的电极材料是人们研究的重点。本文试求通过将碳纳米管与活性纳米铁颗粒复合来提高材料的性能;通过水热-热分解法制备出具有优良超级电容性能的Co3O4电极材料。(1)本文以有机金属化合物二茂铁为原料,采用简易的化学气相沉积法,一步合成了Fe/CNTs纳米复合材料。纳米单质铁沉积在碳纳米管内壁上形成复合纳米结构,碳纳米管为单质铁提供限域环境,可以有效防止铁颗粒的团聚,增加电解质离子与活性物质的反应活性位点。电化学测试结果表明Fe/CNTs复合材料表现为明显的赝电容特性,具有优于CNTs的电容性能,在0.3 A·g-1电流密度时Fe/CNTs复合材料的比电容值为157 F·g-1,CNTs的比电容值为84 F·g-1,经1000次循环充放电后Fe/CNTs复合材料的电容值保持为初始容量的78%。另外,鉴于零价铁在水处理领域的广泛应用,进一步对Fe/CNTs的还原吸附性能进行了研究,结果表明:在一定条件下Fe/CNTs对偶氮染料与Cr(Ⅵ)的去除率达90%以上。(2)采用水热-热分解法,通过改变反应条件制备了花状结构的Co3O4和六面体结构的Co3O4。利用XRD和SEM对材料进行形貌结构表征,结果表明:两者均为立方晶系、尖晶石结构的Co3O4;两种结构的Co3O4均由纳米片层组装而成,但花状Co3O4的纳米片层厚度小于六面体Co3O4,有利于缩短电解质离子的传输距离。电化学测试结果表明花状Co3O4具有优于六面体Co3O4的比电容值,在电流密度为0.5 A·g-1时,花状Co3O4和六面体Co3O4的比电容值分别为244 F·g-1和175 F·g-1;六面体Co3O4具有较好的循环稳定性,经1000次循环充放电后电容保持率为86%。
[Abstract]:As a new type of energy storage device, supercapacitors are characterized by high power density, high charge and discharge speed, good cycle stability and environmental friendliness. It has been widely used in modern power systems and attracted more and more attention from scientists at home and abroad. Among them, the properties and morphology of electrode materials are the key factors affecting the performance of supercapacitors. How to improve the capacitance of electrode material and how to prepare electrode material with excellent capacitance is the focus of research. In this paper, we try to improve the properties of electrode materials by combining carbon nanotubes with active nano-iron particles. Co3O4 electrode material with excellent super capacitance was prepared by hydrothermal thermal decomposition method. In this paper, the organometallic compound ferrocene was used as raw material, and a simple chemical vapor deposition method was used. Fe/CNTs nanocomposites were synthesized in one step. Nanosized iron deposits on the inner wall of carbon nanotubes to form composite nanostructures. Carbon nanotubes provide a limited environment for simple iron, which can effectively prevent the agglomeration of iron particles. The electrochemical test results show that Fe/CNTs composites exhibit obvious pseudo-capacitance properties, which are superior to those of CNTs. When the current density is 0.3 A 路g ~ (-1), the specific capacitance of Fe/CNTs composites is 157F 路g-1. The specific capacitance of Fe/CNTs composites is 84 F 路g ~ (-1) after 1000 cycles. In addition, the capacitance of Fe/CNTs composites is 78% of the initial capacity after 1000 cycles. In addition, in view of the wide application of zero-valent iron in the field of water treatment, The reduction and adsorption properties of Fe/CNTs were further studied. The results showed that the removal rate of azo dyes and Cr (鈪，

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