CdS量子点敏化ZnO纳米棒阵列电极的制备和光电化学性能  

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

作　　者：张桥保[1] 冯增芳[1] 韩楠楠[1] 林玲玲[1] 周剑章[2,1] 林仲华[2,1] 

机构地区：[1]厦门大学化学化工学院化学系,福建厦门361005 [2]厦门大学固体表面物理化学国家重点实验室,福建厦门361005

出　　处：《物理化学学报》2010年第11期2927-2934,共8页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(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0.1mol·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380nm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.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-toelectron 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 quantum dots reduced the recombination of electron and hole pairs resulting in an enhancement in the photocurrent.

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 

分 类 号：TB383.1[一般工业技术—材料科学与工程]