TiO2 nanotube templated electron donor/acceptor architectures

我们计划利用最近在制备定义良好、空间分离的TiO2纳米管方面的进展，将光活性有机分子沉积在管壁上，并进入管的内外空间。这种模板方法将使我们能够在前所未有的环境中研究光诱导电子转移，并最终导致难以捉摸的交叉异质结太阳能电池的制造。TiO2纳米管将在Schmuki组中生长，并在TiO2纳米管内壁上装饰由von Delius制备的定制有机电子给体单层。在这些简单的结构中，我们将合作研究分子特性（如间隔长度或锚定基团）如何影响到半导体衬底的光诱导电子转移（光谱学和动力学）的动力学和效率。von Delius将设计和合成电子受体/锚基团缀合物，而Schmuki将采用他的团队最近开发的一种填塞方案，选择性地将电子给体沉积在TiO2纳米管的内壁上，将电子受体沉积在外壁上。正如最近在原理验证实验中所证明的那样，通过EDS-TEM进行的“元素映射”将在为所需的选择性固定提供证据方面发挥核心作用。除了结构表征外，我们还将研究光致电子转移在多大程度上以及通过哪些供体/受体对在TiO2壁上发生。在项目的最后阶段，von Delius将利用他在正交动态共价反应方面的丰富经验，设计和合成复杂的双功能分子，用于选择性填充Schmuki的TiO2纳米管的内外空间。供体/受体结构域的大小将协同微调，以优化激子寿命，从而有可能为实现互指异质结太阳能电池铺平道路。

We plan to make use of recent progress in the preparation of well-defined, spatially separated TiO2 nanotubes for the deposition of photoactive organic molecules onto the walls and into the inner and outer space of the tubes. This template approach will allow us to study photoinduced electron transfer in an unprecedented environment and could ultimately lead to the fabrication of the elusive interdigitated heterojunction solar cell. TiO2 nanotubes will be grown in the group of Schmuki, and the inner wall of TiO2 nanotubes will be decorated with monolayers of tailor-made organic electron donors prepared by von Delius. In these simple architectures, we will collaboratively investigate how molecular properties such as spacer length or anchoring group, affect the kinetics and the efficiency of photoinduced electron transfer (spectroscopy and kinetics) to the semiconductor substrate. While von Delius will design and synthesize electron acceptor/anchor group conjugates, Schmuki will employ a corking protocol recently developed in his group to selectively deposit electron donors onto the inner walls and electron acceptors onto the outer walls of the TiO2 nanotubes. "Elemental mapping" by means of EDS-TEM, as recently demonstrated in proof-of-principle experiments, will play a central role in providing evidence for the desired selective immobilization. In addition to the structural characterization, we will study to which extent and with which donor/acceptor pairs, photoinduced electron transfer occurs across the TiO2 walls. In the final stage of the project, von Delius will make use of his extensive experience with orthogonal dynamic covalent reactions to design and synthesize sophisticated bifunctional molecules for the selective filling of the inner and outer space of Schmuki's TiO2 nanotubes. The size of donor/acceptor domains will be fine-tuned collaboratively, in order to optimize exciton lifetime, thus potentially paving the way towards the realization of an interdigitated heterojunction solar cell.