染料敏化太阳能电池石墨烯基对电极的制备与应用

发布时间：2018-08-28 16:35

【摘要】：当今世界能源问题日益严峻,因此发展可再生能源迫在眉睫。常见可再生能源包括风能、潮汐能、地热能及太阳能等,其中染料敏化太阳能电池由于其价格低廉、制备过程简单环保、光电转换效率及稳定性高等优点而成为研究重点。染料敏化太阳能电池主要由载有纳米二氧化钛的光阳极、电解液及对电极组成,其中对电极的主要作用是收集外电路电子,催化I3-还原为I-,保证电池反应的快速进行。目前常用的对电极材料为贵金属铂(Pt),但Pt的储量有限,且极易被电解液腐蚀,影响电池的稳定性,因此发展高效价廉的Pt替代材料尤为重要。碳纳米材料具有独特的结构特点与物理化学性质,如高比表面积,高导电性,高催化活性,而且成本低,因此可以用来替代染料敏化太阳能电池中传统的Pt对电极,具有良好的应用前景,其中石墨烯(G)更是因为其优异的性能而备受关注。本文以氧化石墨烯(GO)及G为研究对象,分别合成了GO诱导的双面柱撑聚苯胺(PANI/GO)以及多褶皱杂原子掺杂石墨烯(CHDG),将其用作染料敏化太阳能电池对电极,研究了其对I3-的催化还原性能。研究内容主要包括:以GO为基底,低温条件下,苯胺单体在其片层上原位聚合生成均匀排布的PANI纳米锥。GO表面带有大量含氧官能团,聚合过程中将成为聚合物单体的成核位点,通过控制反应条件,单体在石墨烯晶面上成核、生长,得到双面柱撑聚苯胺结构。与纯PANI对电极及Pt对电极相比,PANI/GO复合材料对电极对I3-具有更优的催化活性,这源于双面柱撑PANI较普通PANI表面形貌发生改变,因此其催化活性及导电性均得到改善。当苯胺单体与GO起始质量比为10:1时,DSSCs的光电转换效率达到最高的8.19±0.08%。以GO为碳源,聚苯乙烯(PS)球为模板,硫脲为氮源及硫源,先水热后高温退火处理,制备多褶皱(C)及杂原子掺杂(HD)的石墨烯-CHDG。水热法石墨烯凝胶形成过程中,PS球与GO片层充分接触、挤压,使G片层生成大量褶皱;高温退火将G进一步还原,同时硫脲高温分解,N/S原子进入石墨烯晶格缺陷,得到CHDG。与纯G,CG,HDG及Pt对电极相比,当多褶皱与杂原子掺杂同时存在时,CHDG做对电极的DSSCs光电转换效率达到8.32±0.09%,同时,DSSCs的稳定性也较Pt更好。
[Abstract]:Nowadays, the energy problem of the world is becoming more and more serious, so it is urgent to develop renewable energy. The common renewable energy sources include wind energy, tidal energy, geothermal energy and solar energy. Among them, dye sensitized solar cells have become the focus of research because of their low price, simple preparation process, environmental protection, high efficiency and stability of photovoltaic conversion. Dye-sensitized solar cells are mainly composed of photoanode, electrolyte and counter electrode containing nano-TiO _ 2. The main function of the photoanode is to collect the electrons of external circuit, catalyze the reduction of I _ 3- to I-so as to ensure the rapid reaction of the cell. At present, the common counter electrode material is platinum (Pt), of noble metal, but the storage of Pt is limited, and it is easy to be corroded by electrolyte, which affects the stability of battery. Therefore, it is very important to develop high efficiency and low price Pt substitute material. Carbon nanomaterials have unique structural characteristics and physical and chemical properties, such as high specific surface area, high conductivity, high catalytic activity, and low cost, so they can be used to replace the traditional Pt counter electrodes in dye sensitized solar cells. It has a good application prospect, among which graphene (G) has attracted much attention because of its excellent performance. In this paper, graphene oxide (GO) and graphene oxide (G) were used as dye sensitized solar cell counter electrodes, GO induced double columnar Polyaniline (PANI/GO) and multi-fold doped graphene (CHDG), were synthesized, respectively. The catalytic reduction of I-3-was studied. The main research contents are as follows: at low temperature, aniline monomer is polymerized on the surface of PANI nanocone. Go with large amount of oxygen-containing functional groups, which will become nucleation site of polymer monomer in the polymerization process, at low temperature, aniline monomer is polymerized on the surface of PANI nanocone. By controlling the reaction conditions, the monomer was nucleated and grown on the graphene crystal plane, and the structure of Polyaniline was obtained by double-sided pillared Polyaniline. Compared with pure PANI electrode and Pt opposite electrode, PANI- / go composite has better catalytic activity for I3-, which is due to the change of surface morphology of double-sided pillared PANI compared with that of ordinary PANI, so its catalytic activity and electrical conductivity are improved. When the initial mass ratio of aniline monomer to GO was 10:1, the photoelectric conversion efficiency reached the highest 8.19 卤0.08. Using GO as carbon source, polystyrene (PS) sphere as template, thiourea as nitrogen source and sulfur source, multi-fold (C) and (HD) doped graphene CHDG were prepared by hydrothermal and high-temperature annealing. During the formation of hydrothermal graphene gel, the PS sphere fully contacted with the GO lamellar and extruded, resulting in a large number of folds in the G layer. G was further reduced by high temperature annealing, and the N / S atom of thiourea was decomposed into the lattice defect of graphene at high temperature, and CHDG. was obtained. Compared with pure GG CGN HDG and Pt counter electrodes, the photoconversion efficiency of DSSCs was 8.32 卤0.09 when the multi-fold and hetero-doped electrodes existed simultaneously, and the stability of DSSCs was better than that of Pt.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM914.4

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