染料敏化太阳能电池新型对电极的制备及研究

发布时间：2018-03-08 07:23

本文选题：染料敏化太阳能电池　切入点：石墨烯　出处：《东南大学》2016年硕士论文　论文类型：学位论文

【摘要】：染料敏化太阳能电池(DSSC)因其理论光电转换效率高、成本低廉、制备工艺简单等优点引起了学术界及工业界极大的研究兴趣,成为近些年的研究热点。而对电极是染料敏化太阳能电池的重要组成部分,其催化活性、导电能力、化学稳定性等方面的性能很大程度上决定了电池的光伏性能。铂金属因其优良的催化活性和导电性,成为最常用的对电极材料,但是由于铂金属的储量低、价格昂贵,而且在r/I3-电解质体系中容易被腐蚀,制约了DSSC的产业化。为了探索价格低廉且性能优良的对电极材料,本论文试图将石墨烯与过渡金属硒化物复合,作为对电极材料应用到DSSC中。主要的研究内容和结果如下：(一)采用改进的Hummers法制备了氧化石墨烯,在导电玻璃FTO上制得石墨烯导电薄膜作为染料敏化太阳能电池的对电极。扫描电子显微镜(SEM)和透射电子显微镜(TEM)显示制得的石墨烯表面有许多层次鲜明的褶皱,可以增大与电解质的接触面积。对比石墨烯对电极和铂对电极的电化学阻抗参数,发现单纯的石墨烯作为对电极材料在I-/I3电解质中对I3-的催化性能与铂之间还有一定的差距。石墨烯基DSSC的光电转换效率为5.24%,是铂基DSSC的61.5%。(二)利用改进的Hummers法制备的氧化石墨烯,通过水热法制备了FeSe_2/rGO复合材料,并首次将其作为染料敏化太阳能电池的对电极材料。X射线衍射(XRD)分析表明合成的FeSe_2是纯相的,SEM照片和TEM照片显示FeSe_2纳米棒成功负载到石墨烯的表面,同时FeSe_2高的结晶度。循环伏安测试、电化学阻抗测试、塔菲尔测试表明FeSe_2/rGO对电极具有很好的导电性和催化活性,在I-/I3-电解质中对I3-的电催化性能要优于Pt对电极、FeSe_2对电极和rGO对电极。光电流密度-电压(J-V)曲线测试表明基于FeSe_2/rGO对电极的DSSC的光电转换效率达到了8.90%,相比基于铂对电极的DSSC提高了4.46%。同时连续循环伏安测试表明FeSe_2/rG O对电极在r/13-电解质中比Pt对电极有更好的稳定性。(三)通过水热法制备了NiSe_2/rGO复合材料,利用旋涂法制备得到NiSe_2/rG O导电薄膜作为染料敏化太阳能电池的对电极。SEM照片显示合成的NiSe_2成纳米球状,通过TEM照片进一步分析得到NiSe_2纳米球由纳米颗粒组成。由于NiSe_2纳米球和纳米颗粒的存在增大了石墨烯片间的距离,从而形成介孔结构,极大的增加了NiSe_2/rGO对电极与电解质的接触面积。根据对电极的电化学测试以及DSSC的光伏性能表征结果,我们发现,相比铂对电极、纯石墨烯对电极和NiSe_2对电极,NiSe_2/rGO对电极在I-/13-电解质中有最小的峰位电差(Epp)和最低的电荷转移阻抗。同时N iSe_2/rGO基DSSC的光电转换效率达到了9.00%,相比铂基DSSC提高了5.63%。
[Abstract]:Dye-sensitized solar cell (DSSC) has attracted great research interest in academia and industry because of its advantages of high theoretical photoelectric conversion efficiency, low cost and simple preparation process. The opposite electrode is an important component of dye sensitized solar cells, and its catalytic activity, conductivity, Due to its excellent catalytic activity and conductivity, platinum has become the most commonly used opposite electrode material, but because of its low reserves, platinum is expensive. Moreover, it is easy to be corroded in the R / I _ 3-electrolyte system, which restricts the industrialization of DSSC. In order to explore the low cost and excellent performance of the opposite electrode material, this paper attempts to combine graphene with the transition metal selenide. The main research contents and results are as follows: (1) graphene oxide was prepared by improved Hummers method. Graphene conductive thin films prepared on conductive glass FTO are used as opposite electrodes for dye sensitized solar cells. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the graphene surface has many distinct folds. Compared the electrochemical impedance parameters of graphene to electrode and platinum to electrode, It was found that there was still a gap between the catalytic performance of graphene as a counter electrode material for I _ 3- in I-R _ (3) electrolyte and platinum. The photoelectricity conversion efficiency of graphene based DSSC was 5.24, which was 61.5% of that of platinum-based DSSC. (2) the improved Hummers method was used. Graphene oxide, FeSe_2/rGO composites were prepared by hydrothermal method. For the first time, it was used as the opposite electrode material for dye sensitized solar cells. X-ray diffraction (XRD) analysis showed that the synthesized FeSe_2 was pure phase FeSe_2 and TEM photos showed that FeSe_2 nanorods were successfully loaded onto the surface of graphene. At the same time, the high crystallinity of FeSe_2, cyclic voltammetry, electrochemical impedance test and Tafel test show that FeSe_2/rGO has good conductivity and catalytic activity to the electrode. The electrocatalytic performance of I3- in I-P / I3- electrolyte is better than that in Pt pair electrode FeSe2 pair and rGO pair electrode. The photocurrent density-voltage J-V curve test shows that the photoconversion efficiency of DSSC based on FeSe_2/rGO to electrode is 8.90, compared with that based on platinum. At the same time, continuous cyclic voltammetry showed that FeSe_2/rG O pair electrode had better stability than Pt pair electrode in r / 13 electrolyte. (3) NiSe_2/rGO composites were prepared by hydrothermal method. NiSe_2/rG O conductive film was prepared by spin-coating method as the opposite electrode of dye sensitized solar cell. The NiSe_2 nanospheres were further analyzed by TEM photographs. Because of the existence of NiSe_2 nanospheres and nanoparticles, the distance between graphene wafers was increased, thus the mesoporous structure was formed. The contact area between NiSe_2/rGO pair electrode and electrolyte was greatly increased. Based on the electrochemical test of the electrode and the photovoltaic performance characterization of DSSC, we found that compared with platinum pair electrode, The pure graphene pair electrode and the NiSe_2 pair electrode have the smallest peak potential difference (Eppp) and the lowest charge transfer impedance in I / 13 electrolyte. At the same time, the photoelectric conversion efficiency of NiSe_2/rGO based DSSC has reached 9.00, which is 5.63% higher than that of platin-based DSSC.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM914.4

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