【作者】 李太平；

【导师】 王世敏；

【作者基本信息】 湖北大学 ， 高分子化学与物理， 2013， 硕士

【摘要】 石墨烯独特的结构赋予它卓越的物理化学性能,作为一种新兴的二维材料,它在传感器、超级电容器、锂离子电池、太阳能电池等电化学领域有着广阔的应用前景,开辟了材料科学研究的新领域。本文采用氧化还原法制备出了石墨烯粉末,然后以石墨烯为前驱体,采用不同的方法来制备石墨烯纳米复合材料,对复合材料的电学性能进行了一系列的研究。并组装以复合物薄膜为对电极的染料敏化太阳能电池(Dye-sensitized solar cells,DSSCs),研究其光电转换效率的影响机理。主要工作如下：1.通过本课题组改进了的氧化还原法制备出氧化石墨烯(GO)和石墨烯(RGO)。X射线衍射(XRD)分析表明氧化石墨烯的层间距离大约是0.87nm。透射电子显微镜(TEM)照片显示所制备的氧化石墨烯均为少层的结构,表面较为平整。傅里叶红外光谱(FT-IR)证明了氧化石墨烯上羟基、羧基和环氧基等含氧功能基团的存在。2.我们分别通过一步还原法和两步还原法制备了低载铂量的铂/石墨烯(Pt/RGO)复合材料。循环伏安法(CV)和电化学交流阻抗测试(EIS)表明复合材料对I-/I3-的还原具有较高的电化学活性。我们采用滴涂法,在FTO导电玻璃上制备了Pt/RGO复合薄膜,并作为对电极,组装的DSSCs的光电转换效率仅比基于铂对电极的低0.91%。3.我们通过原位聚合法合成了聚吡咯-聚苯乙烯磺酸钠/石墨烯(PPy-PSS/RGO)复合材料。利用FT-IR、TEM和SEM对产物的结构和微观形貌进行了表征。通过改变呲咯(Py)单体和RGO的配比,合成了一系列产物。利用滴涂法制备了用于组装DSSCs的复合薄膜对电极。测试发现复合薄膜对电极对I-/I3-还原的电化学活性得到了改善。基于PPy-PSS/RGO复合薄膜对电极的DSSCs的光电转换效率比基于铂对电极的低1.82%。更多还原

【Abstract】 The unique structure of graphene endows it superexcellent properties. As a new two-dimensional material, graphene has wide application prospects in the field of sensors, super-capacitors, lithium-ion batteries, solar cells and other electrochemical, which opens up new areas of research in materials science. In this thesis, we obtained reduced graphene (RGO) by reducing graphite oxide (GO). Then RGO solids were used as precursors to prepare graphene nanocomposites by different methods, and the electrical properties of the composites were also studied. After fabricating nanocomposites films based DSSCs, the effect-mechanism of energy conversion efficiency of the DSSCs was investigated. The dissertation is mainly focused on:1. An improved method for preparation of graphene oxide (GO) and reduced graphene (RGO) by our group. XRD analysis demonstrated that the distance of the GO sheets was about0.87nm, and TEM microphotograph showed that there were a large number of complete few-layer GO sheets, the surfaces were very smooth. FT-IR showed the presence of abundant benzene carboxylic, hydroxyl and epoxide groups in the basal planes of GO.2. We prepared low Pt loading graphene composites by one-step and two-step reduction process in graphene dispersions respectively. Cyclic voltammetry (CV) and electrical impedances analysis (EIS) indicated that the composites had high electrocatalytic activity toward the reduction of iodide/triiodide. We deposited Pt/RGO-composite films on FTO substrates by drop-casting and the films were applied as counter electrodes (CEs) of DSSCs. The energy conversion efficiency of the Pt/RGO CEs based DSSCs was0.91%lower than the Pt CEs based Cells.3. We prepared the PPy-PSS/RGO composites by in-situ polymerization. The composites were characterized by FT-IR, TEM and SEM measurements. A series of products were synthesized by changing the ratio of Py monomer and RGO. The composites films for DSSCs were also prepared by drop-casting. The PPy-PSS/RGO electrodes had an enhanced electrocatalytic activity for iodide/triiodide redox reaction, thus improving the performance of the DSSCs based on these electrodes. The energy conversion efficiency of the PPy-PSS/RGO CEs based DSSCs was1.82%lower than the Pt based Cells.更多还原