物理化学学报 >> 2010, Vol. 26 >> Issue (11): 2927-2934.doi: 10.3866/PKU.WHXB20101113

电化学 上一篇    下一篇

CdS 量子点敏化ZnO纳米棒阵列电极的制备和光电化学性能

张桥保2, 冯增芳2, 韩楠楠2, 林玲玲2, 周剑章1,2, 林仲华1,2   

  1. 1. 厦门大学固体表面物理化学国家重点实验室, 福建厦门361005;
    2. 厦门大学化学化工学院化学系, 福建厦门361005
  • 收稿日期:2010-05-17 修回日期:2010-08-23 发布日期:2010-10-29
  • 通讯作者: 周剑章 E-mail:jzzhou@xmu.edu.cn
  • 基金资助:

    国家自然科学基金(20433040)资助项目

Preparation and Photoeletrochemical Performance of CdS Quantum Dot Sensitized ZnO Nanorod Array Electrodes

ZHANG Qiao-Bao2, FENG Zeng-Fang2, HAN Nan-Nan2, LIN Ling-Ling2, ZHOU Jian-Zhang1,2, LIN Zhong-Hua1,2   

  1. 1. State Key Laboratory of Physical Chemistry of the Solid Surface, Xiamen University, Xiamen 361005, Fujian Province, P. R. China;
    2. Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian Province, P. R. China
  • Received:2010-05-17 Revised:2010-08-23 Published:2010-10-29
  • Contact: ZHOU Jian-Zhang E-mail:jzzhou@xmu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20433040).

摘要:

采用连续式离子层吸附与反应法制备了CdS 量子点敏化的ZnO 纳米棒电极. 应用扫描电子显微镜(SEM)、X 射线衍射(XRD)和透射电子显微镜(TEM)对CdS 量子点/ZnO 纳米棒电极的形貌、晶型和颗粒尺寸进行了分析和表征;采用光电流-电位曲线和光电流谱研究了不同CdS 循环沉积次数及不同沉积浓度对复合电极的光电性能影响. 结果表明, 前驱体浓度都为0.1 mol·L-1且沉积15 次敏化后的ZnO 纳米棒阵列电极光电性能最好. 与单纯的ZnO 纳米棒阵列电极和单纯的CdS 量子点电极相比, 其光电转换效率显著提高, 单色光光子-电流转换效率(IPCE)在380 nm处达到76%. 这是因为CdS量子点可以拓宽光的吸收到可见光区, 并且在所形成的界面上光生载流子更容易分离. 荧光光谱实验进一步说明了光电增强的原因是, 两者间形成的界面中表面态大大减少,有利于减少光生电子和空穴的复合.

 

关键词: ZnO 纳米棒阵列, CdS量子点, CdS 量子点/ZnO纳米棒, 连续式离子层吸附与反应法, 光电化学性能

Abstract:

We sensitized CdS quantum dots on a ZnO nanorod array electrode by the successive ionic layer adsorption and reaction method. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM) experiments were performed to characterize the morphology, crystalline phase, and grain size of the CdS quantum dot sensitized ZnO nanorod array electrodes. The effect of CdS deposition cycle number and the precursor concentration were studied by photocurrent-potential characteristics and photocurrent spectra. The results showed that the best photoelectrochemical performance was obtained at 0.1 mol·L-1 for both Cd2+ and S2- after 15 cycles. Meanwhile, the composite films exhibited a remarkably enhanced photoelectric conversion efficiency compared with the ZnO nanorods array films and with CdS quantum dot electrodes. The monochromatic incident photon-to- electron conversion efficiency (IPCE) was as high as 76% at 380 nm. This may be attributed to the broad light harvesting capability of CdS and the efficient separation of photogenerated carriers on its interface. The reason for this enhancement was further confirmed by a photoluminescent experiment. The results showed that sensitization with CdS quantumdots reduced the recombination of electron and hole pairs resulting in an enhancement in the photocurrent.

 

Key words: ZnO nanorod array, CdS quantum dots, CdS quantumdots/ZnO nanorods, Successive ionic layer adsorption and reaction method, Photoelectrochemical performance

MSC2000: 

  • O646