物理化学学报 >> 2014, Vol. 30 >> Issue (8): 1487-1494.doi: 10.3866/PKU.WHXB201405272

电化学和新能源 上一篇    下一篇

聚合溶液pH值对染料敏化太阳电池中聚吡咯对电极结构和性能的影响

苏佳1,2, 芦姗2, 王莎莎2, 张雪华2, 付玉彬1, 贺涛2   

  1. 1. 中国海洋大学材料科学与工程研究院, 山东青岛 266100;
    2. 国家纳米科学中心, 北京 100190
  • 收稿日期:2014-04-17 修回日期:2014-05-26 发布日期:2014-07-18
  • 通讯作者: 张雪华, 付玉彬, 贺涛 E-mail:zhangxh@nanoctr.cn;ffyybb@ouc.edu.cn;het@nanoctr.cn
  • 基金资助:

    科技部(2010DFB63530)、国家自然科学基金(51043010,21203039)和中国科学院项目百人资助项目

Influence of pH Values on the Structure and Performance of a Polypyrrole Counter Electrode for Dye-Sensitized Solar Cells

SU Jia1,2, LU Shan2, WANG Sha-Sha2, ZHANG Xue-Hua2, FU Yu-Bin1, HE Tao2   

  1. 1. Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100, Shandong Province, P. R. China;
    2. National Center for Nanoscience and Technology, Beijing 100190, P. R. China
  • Received:2014-04-17 Revised:2014-05-26 Published:2014-07-18
  • Contact: ZHANG Xue-Hua, FU Yu-Bin, HE Tao E-mail:zhangxh@nanoctr.cn;ffyybb@ouc.edu.cn;het@nanoctr.cn
  • Supported by:

    The project was supported by the Ministry of Science and Technology of China (2010DFB63530), National Natural Science Foundation of China (51043010, 21203039), and Hundred-Talent Program of Chinese Academy of Sciences.

摘要:

电化学合成聚吡咯(PPy)时,聚合电解液的pH 值对PPy 薄膜的形貌和性质有较大的影响,进而影响PPy薄膜对I-/I3-的电催化活性以及基于PPy对电极(CE)的染料敏化太阳电池(DSSCs)的光电转换性能. 本文采用电化学恒电位方法,在掺杂氟的SnO2(FTO)导电玻璃上合成出了对甲苯磺酸根离子掺杂的聚吡咯(PPy-TsO)电极,并将其作为DSSCs 的对电极. 通过改变吡咯聚合时聚合电解液的pH值,借助扫描电镜(SEM)、紫外-可见(UV-Vis)吸收光谱、X-射线光电子能谱(XPS)和循环伏安(CV)等表征技术,详细探讨了聚合溶液pH值对PPy CE形貌、结构及其对I-/I3-的电催化性能的影响. 研究发现在pH 2.0下合成的聚吡咯对阴离子掺杂率最高且链共轭性最佳,具有对I-/I3-氧化还原介质最强的催化能力,基于此PPy CE的电池光电转化效率也最高.pH 值太大或太小都不利于生成具有高掺杂率和高催化活性的PPy电极,组装成DSSCs后的光电转换效率也较低.

关键词: 聚吡咯, 电化学聚合, pH值, 电催化活性, 对电极, 染料敏化太阳电池

Abstract:

The pH of the solution used to produce an electro- polymerized polypyrrole (PPy) film has a significant impact on the morphology and properties of the resulting film and, by extension, on the electrocatalytic activity of the film for the I-/I3- redox reaction. Accordingly, the performance of dye-sensitized solar cells (DSSCs) based on PPy counter electrodes (CEs) is affected by solution pH. In this study, p-toluene sulfonate ion-doped PPy (PPy-TsO) CEs on fluorine-doped tin oxide (FTO) glass substrates were fabricated using an electrochemical method under a constant bias in solutions with various pH values. The effect of the pH of the synthetic solution on the morphology, structure, and electrocatalytic activity during the I-/I3- redox reaction of the obtained PPy CEs was thoroughly investigated by scanning electron microscopy (SEM), UV-Vis absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV). A pH value of 2.0 was found to represent the optimal value, since the PPy-TsO film produced at this pH exhibited the highest degree of doping, the longest conjugation length, and the highest catalytic activity. When working as the CE of a DSSC, this film also showed the highest power conversion efficiency. Films synthesized at pH values either above or below 2.0 exhibited inferior properties and lower performance when in DSSCs.

Key words: Polypyrrole, Electrochemical polymerization, pH value, Electrocatalytic activity, Counter electrode, Dye-sensitized solar cell

MSC2000: 

  • O646