基于Co、Mn、Ni硫族化合物纳米材料的合成及性能研究

发布时间：2018-04-20 12:42

本文选题：过渡金属 + 硫族化合物　；参考：《安徽师范大学》2017年硕士论文

【摘要】：由于过渡金属材料有着独特的物理和化学性能,从而广泛的应用在催化、储能、电磁、传感等领域。其中,过渡金属Co、Mn、Ni硫族化合物纳米材料具有制备方法简单,形貌结构易控制合成,电化学活性高等优点,引起了研究者们的广泛关注。对于当今比较前沿的超级电容器储能材料而言,制备的方法简单及材料的性能优越一直是科研者的一致追求。本论文通过水热、离子交换及材料复合等方法使过渡金属Co、Mn、Ni硫族化合物具有独特的纳米结构,从而使其具有突出的导电性、较高的电化学活性、较大的比表面积,表现出优异的电化学储能性能。本论文的主要研究内容如下:1.通过低温水热法及泡沫镍作为模板的条件下合成出超薄多孔Co_3O_4的前躯体Co(OH)2,前躯体Co(OH)2再经高温退火处理后即得超薄介孔状Co_3O_4纳米片。通过TME和BET表征后发现,Co_3O_4纳米片由大量介孔组成,孔径约为2-12 nm,且退火后的比表面积是前躯体的2.24倍,由此可见孔隙的大量生成。将制备的Co_3O_4纳米片作为超级电容器电极材料,在2 M NaOH电解液里当电流密度为1 A g-1时电容大小为610F g-1。在4 A g-1电流密度下循环3000圈后,比电容仍可保持在94.5%。将其应用在非对称电极中,表现出优异的性能。由以上可得超薄多孔Co_3O_4纳米片是一种不错的储能电极材料。2.在有了超薄多孔Co_3O_4纳米片以后,通过简单的水热条件下的离子交换方法,将O原子替换成S原子。由于负载Co_3O_4的泡沫镍参与部分反应,故产物中包含部分NiS。在2 M KOH电解液中,在同样的电流密度下,过渡金属硫化物Co3S4/NiS的比电容是原先超薄多孔Co_3O_4的12倍。在非对称电极测试中,4 mA cm-2下,过渡金属硫化物Co3S4/NiS的比电容为1810 mF cm-2,其电位窗口可达1.6 V,在功率密度为32 W m-2下,能量密度为6.44 W h m-2。我们将其制作成模拟的储能器件应用时,其可以令5个LED持续工作8分钟以上。3.通过两步水热法合成出过渡金属氧化物的复合物MnO2@NiMo O4,并研究了其作为柔性超级电容器的储能性能。以MnO2纳米线为模板,然后利用水热法在MnO2纳米线外面生长出Ni MoO4纳米片。结构表征后发现该过渡金属氧化物复合物是以MnO2纳米线为核的异质结构。以这种异质结构的过渡金属氧化物为正极,多孔碳作为负极,制造柔性不对称超级电容器,在10 mV s-1的扫描速率下拥有186.8 F g-1的高电容,在超过20000次循环后比电容量保留132.7%,在电极组件弯曲30到150o(相应的曲率半径为4.5 mm至小至1.0 mm),弯曲后的比电容没有明显变化。这样优越的性能说明MnO2@NiMoO4是一种有潜力的超级电容器电极材料。
[Abstract]:Due to the unique physical and chemical properties of transition metal materials, it is widely used in the fields of catalysis, energy storage, electromagnetic, sensing and so on. Among them, Co, Mn, Ni sulfur compound nanomaterials have the advantages of simple preparation method, easy to control synthesis of morphology and structure, and high electrochemistry activity, which have aroused the widespread concern of the researchers. As far as the advanced supercapacitor energy storage materials are concerned, the simple preparation method and the superior performance of the materials have always been the consistent pursuit of the researchers. This paper makes the transition metal Co, Mn, Ni sulfur compounds with unique nanostructures by the methods of hydrothermal, ion exchange and material recombination, so that they have outstanding conductivity. High electrochemical activity, larger specific surface area and excellent electrochemical energy storage performance. The main contents of this paper are as follows: 1. the precursor Co (OH) 2 of ultrathin porous Co_3O_4 was synthesized under the condition of low temperature hydrothermal method and nickel foam as a template, and the precursor Co (OH) 2 was then annealed at high temperature, and the ultrathin mesoporous Co_3 was obtained. The O_4 nanoscale was characterized by TME and BET. It was found that the Co_3O_4 nanoscale was composed of a large number of mesoporous pores, with an aperture of about 2-12 nm, and the specific surface area after annealing was 2.24 times that of the precursor. Thus, a large number of pores were produced. The prepared Co_3O_4 nanoscale was used as a supercapacitor electrode material and the current density was 1 A g-1 in the 2 M NaOH electrolyte. The capacitance is 610F g-1. after 3000 cycles at 4 A g-1 current density, and the specific capacitance can still be kept in the asymmetric electrode with the specific capacitance at 94.5%.. The super thin porous Co_3O_4 nanoscale is a good energy storage electrode material.2. after a super thin porous Co_3O_4 nanoscale, through simple water. The ion exchange method under thermal conditions replaced the O atoms into S atoms. Due to the partial reaction of the nickel foam loaded with Co_3O_4, the product contained part of the NiS. in the 2 M KOH electrolyte, and at the same current density, the specific capacitance of the transition metal sulfide Co3S4/NiS was 12 times that of the original ultra thin porous Co_3O_4. In the asymmetric electrode test, 4 Under mA cm-2, the specific capacitance of the transition metal sulfide Co3S4/NiS is 1810 mF cm-2, its potential window can reach 1.6 V, the power density is 32 W m-2, and the energy density is 6.44 W h m-2.. When we make it into a simulated energy storage device, it can make 5 LED for more than 8 minutes more than two step hydrothermal method to synthesize the transition metal oxygen. The compound MnO2@NiMo O4 of the compound is used as the energy storage performance of the flexible supercapacitor. The MnO2 nanowires are used as the template, and the Ni MoO4 nanoscale is grown outside the MnO2 nanowires. The structural characterization shows that the transition metal oxide complex is a heterogeneous structure with the MnO2 nanowire nucleus. The transition metal oxide is the positive pole, and the porous carbon is used as the negative electrode to make the flexible asymmetric supercapacitor, with a high capacitance of 186.8 F g-1 at the scanning rate of 10 mV. After more than 20000 cycles, the specific capacity is 132.7%, and the electrode assembly is bent 30 to 150O (the radius of curvature of the phase is 4.5 mm to 1 mm) and is bent after bending. There is no obvious change in specific capacitance. This superior performance shows that MnO2@NiMoO4 is a potential supercapacitor electrode material.

【学位授予单位】：安徽师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1

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