基于TiO2/SrTiO3异质结纳米管阵列薄膜的高光电转化效率DSSCs体系研究

Great attentions have been focused on dye-sensitized solar cells, which was an important option of utilization of solar energy, being an important role in utilization of solar energy effectively. The conversion of photo to electron was limited greatly because of the defects of photoanode thin film materials (TiO2 film), such as larger band gap, low adsorption capacity, unstable of dye-sensitized agent, and the low dye molar extinction coefficient and narrow spectral response. According to this analysis, free standingTiO2/SrTiO3 heterojunction nanotube array films are proposed to fabricated using a three-step anodic oxidation combined with a hydrothermal process in this project, and then CdS being sensitizer which will be assembled in dye-sensitized solar cells. Herein, double layer scattering composed with anatase-rutile surface face-junction will be introduced into this target sysytem to enforce trasfermation of electron. photoelectric properties and the electron transition mechanism will be carried out to study the enhancement of photoelectric conversion efficiency and theoretical research in this project.

染料敏化太阳能电池作为太阳能利用的重要途径，因在高效利用太阳能上发挥着重要作用而倍受关注。但光阳极薄膜材料（TiO2薄膜）自身较大的禁带宽度和染料敏化剂在其表面吸附量难于提高且不稳定，以及染料摩尔消光系数低和对光谱响应范围窄，均成为限制太阳光利用率和光电转化效率提高的关键因素。基于此，本研究提出以改进多步阳极氧化法与水热法相结合制备免支撑TiO2/SrTiO3异质结纳米管阵列薄膜，并进行CdS敏化，结合于异相结双层光散射粘结层组装染料敏化太阳能电池，并进行光电性能及光生电子跃迁机理研究；以N719染料体系验证光阳极光稳定性并优化电池构造参数后，将吩噻嗪基染料引入优化后的染料敏化太阳能电池体系来提高光电转化效率的实验研究和理论探索。

本项目通过耦合阳极氧化和水热法合成高活性异质结TiO2/SrTiO3纳米管，以阳极氧化的无定型TiO2(N掺杂TiO2，简化为N-TiO2)纳米管为初始反应物和“骨架”模板在水热Sr(OH)2溶液中发生原位取代的溶解-沉淀反应生成SrTiO3颗粒，经高温处理后得到高活性异质结TiO2/SrTiO3(N掺杂TiO2/SrTiO3，简化为N-TiO2/SrTiO3)纳米管。对所合成高活性异质结进行结构和组成表征分析，表明该高活性异质结中锐钛矿TiO2占主导，且其锐钛矿TiO2高活性{001}晶面发生明显的取向生长；以上述高活性异质结为阳极进行光电化学测试和光电催化降解甲基蓝(MB)和罗丹明B(Rh. B)实验，发现高活性异质结活性对比纯TiO2(或N-TiO2)，其光电催化活性明显增强。这主要归结为高活性{001}晶面和异质结界面及N引入的共同作用。其具体内容为：1).设计与合成高活性异质结TiO2/SrTiO3纳米管；2).高活性异质结TiO2/SrTiO3光电催化机制; 3)可见光响应的高活性异质结N-TiO2/SrTiO3设计、合成及光电催化机制；4）高质量异质结的形成归结于1.5 Pa溅射压强下形成的高{001}TiO2的结晶度、表面相貌、适宜的{001}TiO2薄膜厚度。