State Key Laboratory of New Ceramics & Fine Processing, Department of Material Science and Engineering, Tsinghua University, Beijing 100084, PR China.
Phys Chem Chem Phys. 2011 Sep 21;13(35):15918-24. doi: 10.1039/c1cp21833f. Epub 2011 Aug 8.
A novel heterostructural TiO(2) nanocomposite, which consists of single-crystalline rutile TiO(2) nanorod decorated Degussa P25 nanoparticles, has been fabricated through a facile acidic hydrothermal method and successfully applied as the photoanodes for efficient dye-sensitized solar cells. The morphology, crystal structure, specific surface area and pore size distribution of the obtained nanocomposite were systematically investigated by X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM), high resolution transmission electron microscope (HRTEM), selected-area electron diffraction patterns (SAED) and nitrogen adsorption-desorption measurements. Under standard illumination conditions (AM 1.5, 100 mW cm(-2)), devices with these hybrid anodes exhibited considerably enhanced photocurrent density and overall conversion efficiency in comparison with that of the commercial Degussa P25 electrodes, which can be partially attributed to the light scattering effect in the long-wavelength region as evidenced from the incident photon-to-current conversion efficiency (IPCE) response and the diffuse reflectance spectroscopy. More importantly, devices employing these hybrid anodes have demonstrated extended electron lifetimes and larger electron diffusion coefficient as validated by the intensity-modulated photocurrent/photovoltage spectroscopy measurements, which can be mainly ascribed to the fast electron transport and collection superiority of the single-crystalline nanorods.
一种新型的 TiO(2) 纳米复合材料，由单晶金红石 TiO(2) 纳米棒修饰的 Degussa P25 纳米粒子组成，通过简单的酸性水热法制备，并成功地用作高效染料敏化太阳能电池的光阳极。通过 X 射线衍射（XRD）、场发射扫描电子显微镜（FESEM）、高分辨率透射电子显微镜（HRTEM）、选区电子衍射图谱（SAED）和氮气吸附-脱附测量，对所得纳米复合材料的形貌、晶体结构、比表面积和孔径分布进行了系统研究。在标准照明条件（AM 1.5，100 mW cm(-2))下，与商用 Degussa P25 电极相比，这些混合阳极的器件表现出相当大的增强的光电流密度和整体转换效率，这可以部分归因于长波长区域的光散射效应，如从入射光子-电流转换效率（IPCE）响应和漫反射光谱中可以看出。更重要的是，通过强度调制光电流/光电压光谱测量验证了这些混合阳极器件具有延长的电子寿命和更大的电子扩散系数，这主要归因于单晶纳米棒的快速电子传输和收集优势。
