Polymer semiconductors toward efficient photocatalytic H2 production from sea water - understanding and exploiting the presence of ions

全球变暖、日益严重的环境污染以及有限的化石能源资源促使我们的社会发展出一种更加可持续的能源生产和使用方式。光催化悬浮颗粒直接太阳能制氢提供了一个有效的解决方案。然而，到目前为止，光催化析氢（PHE）的效率有限，通常知之甚少，并且忽略了实际重要的海水环境，在海水环境中性能通常会下降，但颗粒基PHE最有希望。在本项目中，我们将首先系统地研究海水离子对现有聚合物半导体的离子效应。时间分辨光谱将为受离子存在和相互作用影响的光物理材料特性提供基本见解。这种活性和性质的研究将集中在亲水的供体-受体（D-A）结构上，这种结构在粒子体异质结（BHJ）中表现得非常有效。接下来，我们将探索用于有机电化学晶体管（OECT）的聚合物材料的光活化工艺，该工艺已被证明可以增强与海水离子相互作用时的电荷稳定性和输运性能。通过这项研究，我们将确定下一代海水光催化剂的候选材料，我们将研究（BHJ）纳米颗粒，并优化其在离子存在下的更高PHE效率。因此，该项目将提供离子效应及其对聚合物材料光催化性能的影响的基本见解，以及通过离子相互作用调节光物理性质的途径。因此，光离子催化是使海水PHE更可行的重要一步，同时揭示了通过环境离子相互作用改变材料性质的可能性，这可扩展到许多其他能量转换过程。

Global warming, increasing environmental pollution and limited fossil energy resources push our society to develop a more sustainable production and use of energy. Direct solar hydrogen production with suspended particles by photocatalysis offers an effective solution. However, until now, photocatalytic hydrogen evolution (PHE) suffers from limited efficiencies, is often poorly understood and neglects the practically important sea water environments, where performance typically decreases, but where particle based PHE would be most promising. In this project, we will first study ionic effects, induced by presence of sea water ions, on state of the art polymeric semiconductors systematically. Time resolved spectroscopy will provide fundamental insights into photophysical material properties that are affected by the presence of and interaction with the ions. This activity and property study will focus on hydrophilic donor-acceptor (D-A) structures, which were shown to perform very efficiently in a particle bulk heterojunction (BHJ). Next, we will explore photo-activation processes of polymer materials used for organic electrochemical transistors (OECT), which were shown to enhance the charge stabilization and transport properties upon interacting with sea water ions. By this, we will identify promising material candidates for next generation sea water photocatalysts, which we will study as (BHJ) nanoparticles and optimize toward higher PHE efficiencies in presence of ions. Thereby, this project will provide fundamental insights in ionic effects and their influence on the photocatalytic performance of polymer materials, as well as pathways to tune photophysical properties by ionic interactions. Photo-Iono-Catalysis hence presents an important step to make sea water PHE more viable, while shedding light on the possibility to modify material properties by environmental ionic interactions, which are extendable to many other energy conversion processes.