【作者】 母静波；

【导师】 陈彬；

【作者基本信息】 东北师范大学 ， 物理化学， 2013， 博士

【摘要】 由于碳纳米纤维（CNFs）具有高导电和导热、高比强度、化学稳定性及其易于表面官能化等优点，因此，逐渐成为复合材料研究的热点。碳纤维复合材料已在催化剂和催化剂载体、锂离子二次电池、光电化学电池和传感器等领域获得了广泛的应用。本论文采用静电纺丝技术和溶剂热方法制备多种碳纳米纤维/金属氧化物功能复合材料，并探究了这些功能复合材料在光催化和超级电容器领域的应用性能，取得的创新性成果如下：1．通过静电纺丝技术和水热方法成功获得了具有一维结构的高催化活性ZnO-CNFs异质结光催化剂，样品通过FE-SEM，EDX，TEM，XRD，XPS和IR光谱测试说明ZnO纳米粒子成功分散生长在CNFs上，通过改变水热过程中醋酸锌和CNFs的比例，可以很好地控制生长在CNFs上ZnO纳米粒子的覆盖密度。由于在ZnO和CNFs间形成的异质结促进了电子和空穴的分离，因此ZnO-CNFs异质结光催化剂在对罗丹明B降解测试中显示了较高的催化活性。另外，ZnO-CNFs异质结光催化剂由于其具有一维特性，因而可以很容易地实现回收再利用，而且其重复利用后光催化效果无明显减弱。2.为了充分利用太阳光对污水进行处理，我们对窄带隙In₂O₃光催化剂进行了改性。首次结合静电纺丝技术和溶剂热方法制备了In₂O₃/CNFs异质结可见光催化剂。在可见光照下，与纯In₂O₃对比显示，In₂O₃/CNFs异质结光催化剂在降解罗丹明B方面显示出了更高的催化效果，良好的催化效果是由于在In₂O₃和CNFs间形成了异质结，这个异质结的存在，加速了光生电子和空穴分离。另外，由于一维纳米纤维特有的性质使得In₂O₃/CNFs异质结可见光催化剂在提高其催化效果的同时提高了其回收循环利用的性能。同时，我们还发现，通过改变添加剂如CO（NH2）2和水的量便可以实现对纳米In₂O₃的形貌的控制，如纳米立方体，纳米簇和纳米粒子，并对纳米结构的In₂O₃形成机理进行了讨论。3.通过静电纺丝技术和水热方法制备了SnO₂/CNFs异质结。结果表明，SnO₂纳米粒子成功负载在CNFs表面上，通过对水热过程中CNFs和SnCl₄.5H₂O的质量比可以控制SnO₂在CNFs表面上的覆盖度。对该材料在超级电容器电极材料方面的电化学性能进行了测试。用1M H₂SO₄溶液作为电解液，对材料进行循环伏安和恒流充放电测试表明，在不同扫描速率下，各样品均显示良好的电容性能。在20mV/s扫速下，样品CS2（CNFs和SnCl₄.5H₂O的质量比为1:7）拥有最高的电容量187F/g,而且经过1000次循环后，其电容量仍然保持在95%以上。良好的电化学性能可能是由于SnO₂/CNFs异质结材料低高电导率以及电解液可以快速传输到SnO₂表面的原因。4利用静电纺丝技术和溶剂热过程，首次成功地在CNFs表面上合成了高分散的Fe₃O₄纳米片层。将Fe₃O₄/CNFs复合材料制成超级电容器电极，并采用采用循环伏安和恒流充放电测试其电化学性能。结果显示，在不同扫描速率下，该材料呈现良好的电容性能。同纯Fe₃O₄相比（83F/g），Fe₃O₄/CNFs复合材料具有更高的比容量（135F/g）。经过一千次循环使用后，Fe₃O₄/CNFs复合材料的电容量仍可达到91%。较高的电容性能是由于在Fe₃O₄/CNFs复合材料中高电导率的一维CNFs降低了Fe₃O₄的电阻。另外，在CNFs表面上高分散和高比表面积的Fe₃O₄纳米片层提高了Fe₃O₄的利用率。最后，我们还讨论了纳米片层状Fe₃O₄在CNFs表面上的形成机理。更多还原

【Abstract】 Carbon nanofibers （CNFs） show high conductivity and thermal conductivity, goodmechanical properties， chemieal stabllity, easy surfac efunctionalized and so on. In thisdissertation, In this dissertation, the valuable explorations have been focused on the designand synthesis of composite material, which has attracted special attention due to its widepotential application in many fields, such as catalysis and catalyst support chemical sensors,chemical cells, lithium-ion batteries, adsorbing material etc. In this dissertation, we employ anovel strategy to fabricate functional CNFs/metallic oxide nanocomposites by combining theelectrospinning technique and the solvothermal method. And the practical applications of theas-prepared functional nanocomposites materials are also investigated. The main researches arelist as follow:1. One-dimensional ZnO-carbon nanofibers （CNFs） heteroarchitectures with highphotocatalytic activity have been successfully obtained by a simple combination ofelectrospinning technique and hydrothermal process. The as-obtained products werecharacterized by field-emission scanning electron microscopy （FE-SEM）, energy-dispersiveX-ray （EDX） spectroscopy, transmission electron microscopy （TEM）, X-ray diffraction（XRD）, X-ray photoelectron spectroscopy （XPS）, and IR spectrum. The results revealed thatthe secondary ZnO nanostructures were successfully grown on the primary CNFs substrateswithout aggregation. And, the coverage density of ZnO nanoparticles coating on the surfaceof the CNFs could be controlled by simply adjusting the mass ratio of zinc acetate to CNFs inthe precursor during the hydrothermal process for the fabrication of ZnO-CNFsheterostructures. The obtained ZnO-CNFs heteroarchitectures showed high photocatalyticproperty to degrade rhodamine B （RB） because of the formation of heteroarchitectures,whichmight improve the separation of photogenerated electrons and holes. Moreover, theZnO-CNFs heteroarchitectures could be easily recycled without the decrease in photocatalyticactivity due to their one-dimensional nanostructural property.2One-dimensional In₂O₃nanocubes/carbon nanofibers （CNFs） heterostructures have beensuccessfully obtained by a simple combination of electrospinning technique and solvothermalprocess for the first time. Photocatalytic tests displayed that the In₂O₃/CNFs heterostructurespossessed a much higher degradation rate of rhodamine B （RB） than the pure In₂O₃undervisible light. The enhanced photocatalytic activity could be attributed to the formation ofheterostructures, which might improve the separation of photogenerated electrons and holes. Moreover, the In₂O₃/CNF heterostructures could be easily recycled without the decrease ofthe photocatalytic activity due to their one-dimensional nanostructural property. Themorphology of the secondary In₂O₃nanostructures （nanocubes, nanoagglomerates ornanoparticles） could be controlled by adjusting the additives including CO（NH2）2and adefined amount of water. The general growth mechanisms for the In₂O₃nanostructures havealso been discussed.3Tin oxide （SnO₂）/carbon nanofibers （CNFs） heterostructures were fabricated by combiningthe versatility of the electrospinning technique and hydrothermal process. The results revealedthat the SnO₂nanostructures were successfully grown on the primary electrospun carbonnanofibers substrates. And, the coverage density of SnO₂nanoparticles coating on the surfaceof the CNFs could be controlled by simply adjusting the mass ratio of CNFs to SnCl₄.5H₂O inthe precursor during the hydrothermal process for the fabrication of SnO₂/CNFsheterostructures. The electrochemical performances of the SnO₂/CNFs heterostructures as theelectrode materials for supercapacitors were evaluated by cyclic voltammetry （CV） andgalvanostatic charge discharge measurement in1M H₂SO₄solution. At different scan rates,all the samples with different coverage densities of SnO₂showed excellent capacitancebehavior. And, the sample CS2（the mass ratio of CNFs to SnCl₄.5H₂O reached1:7） exhibiteda maximum specific capacitance of187F/g at a scan rate of20mV/s. Moreover, after1000cycles, the specific capacitance retention of this sample was over95%. The high capacitivebehavior could be ascribed to the low resistance of SnO₂/CNFs heterostructures and rapidtransport of the electrolyte ions from bulk solution to the surface of SnO₂.4. Highly dispersed Fe₃O₄nanosheets on one-dimensional （1D） carbon nanofibers （CNFs）were firstly fabricated by combining the versatility of the electrospinning technique andsolvent-thermal process. The electrochemical performances of the Fe₃O₄/CNFsnanocomposites as the electrode materials for supercapacitors were evaluated by cyclicvoltammetry （CV） and galvanostatic charge–discharge measurement in1M Na2SO3electrolyte. At different scan rates, the sample showed excellent capacitance behavior.Incomparison to the pure Fe₃O₄（83F/g）, the as-prepared Fe₃O₄/CNFs nanocompositeselectrode exhibited a higher specific capacitance （135F/g）. Meanwhile, the supercapacitordevices of the Fe₃O₄/CNFs nanocomposites exhibited excellent long cycle life along with91%specific capacitance retained after1000cycle tests. The high capacitive behavior couldbe ascribed to the high electrical conductivity and the one-dimensional properties of the CNFsin Fe₃O₄/CNFs nanocomposites, which could decrease the charge transfer resistance of theFe₃O₄. At the same time, the high specific surface area and high level exposure of the Fe₃O₄nanosheets on the surface of the CNFs increased the electrochemical utilization of Fe₃O₄. Finally, a possible mechanism for the formation of the Fe₃O₄nanosheets on the surface ofCNFs was suggested.更多还原