化学学报 ›› 2015, Vol. 73 ›› Issue (10): 1061-1068.DOI: 10.6023/A15040264 上一篇    下一篇

研究论文

SO4-和I-共掺杂的聚苯胺对电极在染料敏化太阳电池中的应用

韩若冰a,b, 芦姗a, 王艳杰a, 张雪华a, 吴强b, 贺涛a   

  1. a 中国科学院纳米系统与多级次制造重点实验室 国家纳米科学中心 北京 100190;
    b 上海电力学院环境与化学工程学院 上海 200090
  • 收稿日期:2015-04-16 出版日期:2015-10-15 发布日期:2015-07-07
  • 通讯作者: 吴强, 贺涛 E-mail: het@nanoctr.cn; zhangxh@nanoctr.cn; qiangwu@shiep.edu.cn
  • 基金资助:

    项目受国家自然科学基金(Nos.21203039,21107069)和科技部国际合作(No.2015DFG62610)资助.

Application of SO4- and I- co-Doped Polyaniline Counter Electrode in Dye-sensitized Solar Cells

Han Ruobinga,b, Lu Shana, Wang Yanjiea, Zhang Xuehuaa, Wu Qiangb, He Taoa   

  1. a CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190;
    b Shanghai University of Electric Power, Shanghai 200090
  • Received:2015-04-16 Online:2015-10-15 Published:2015-07-07
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21203039, 21107069), and the Ministry of Science and Technology of China (No. 2015DFG62610).

采用循环伏安法(CV)在掺杂氟的二氧化锡(FTO)导电玻璃上, 成功聚合了SO4-和I-共掺杂的聚苯胺(PANI)对电极. 利用扫描电子显微镜(SEM)、紫外-可见(UV-Vis)吸收光谱、傅里叶红外(FT-IR)吸收光谱、CV和电化学阻抗谱(EIS)等测试方法详细研究了I-作为第二种掺杂离子及LiI掺杂浓度对所制备的PANI对电极的表面形貌, 结构和对I-/氧化还原电对的催化活性的影响. SEM结果显示在聚合电解液中引入LiI改变了所制备的PANI对电极的形貌, 可提供更多的催化反应活性位点, 同时还改善了薄膜的孔隙性. 值得注意的是, 引入I-共掺杂可在一定程度上使3I-↔ +2e-反应在相应的PANI电极上更容易进行. 在反应体系中 LiI浓度为0.02 mol·L-1时得到的PANI对电极, 组装成电池时获得的电池效率最高可达6.52%, 相当于Pt对电极6.95%的93.8%, 比基于只掺杂 的PANI对电极的光电转换效率提高了16%, 说明 和I-共掺杂的PANI对电极可以提高相应染料敏化太阳电池的光电转换性能, 有望在未来成为Pt对电极的替代材料.

关键词: 聚苯胺, 共掺杂, 电催化活性, 对电极, 染料敏化太阳电池

SO4- and I- co-doped polyaniline (PANI) on fluorine-doped tin oxide (FTO) conductive glass substrates were fabricated via electropolymerization with different LiI concentration and used as counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). The polymerization was performed via cyclic voltammetry (CV) method (0~1.0 V, vs saturated calomel electrode, SCE) at room temperature in aqueous solution, containing 0.35 mol·L-1 aniline monomer, 0.25 mol·L-1 H2SO4 and different concentrations of LiI (0, 0.01, 0.02 and 0.03 mol·L-1). A Pt plate was used as the counter electrode and SCE was used as the reference electrode. The influences of I- doping and the concentration of LiI on surface morphology, structure, and electrocatalytic activity for I-/redox reaction of the obtained PANI CEs were thoroughly studied by scanning electron microscopy (SEM), UV-Vis absorption spectroscopy, fourier transform infrared spectroscopy (FT-IR), CV, and electrochemical impedance spectroscopy (EIS). SEM images indicated that the introduction of LiI into the polymerization solution could change the morphology of the obtained PANI CEs, which could provide more electrocatalytic sites for I-/redox reaction. Meanwhile, the porosity of the as-prepared PANI films was also improved. It is worth noted that I- co-doping could make it easier for 3I- ↔ +2e- reaction on PANI electrodes. The sandwich-type DSSCs were comprised of a N719-sensitized TiO2 working electrode, an as-prepared PANI or Pt electrode as CE, and a redox mediator solution containing 0.1 mol·L-1 LiI, 0.05 mol·L-1 I2, 0.6 mol·L-1 1,2-dimethyl-3-propylimidazolium iodide, and 0.5 mol·L-1 4-tert-butylpyridine in acetonitrile. DSSC based on the PANI CE polymerized with 20 mmol·L-1 LiI showed the best photovoltaic performance, with a solar-to-energy conversion efficiency of 6.52%, which is 93.8% of the efficiency of Pt-DSSC (6.95%) and 116% of that based on PANI CE doped only with SO4-. The results suggest that SO4- and I- co-doped PANI CEs can improve the photovoltaic performance of the resultant DSSCs, and may replace Pt CEs in DSSCs in the future.

Key words: polyaniline, co-doping, electrocatalytic activity, counter electrode, dye-sensitized solar cells