Metal oxide nanostructures for electrochemical and photoelectrochemical water splitting

该研究项目的主要目标是开发用于高效电化学和光驱动水分解的新型金属氧化物纳米形态。我们将采用双管齐下的搜索方法，该方法基于(i)使用高通量DFT计算进行计算筛选，以及（ii）在高通量合成和测试领域与SPP 1613进行密切合作。将开发不同复杂程度的优化纳米形态，包括薄膜模型系统，通过模板创建的多孔纳米结构薄膜和分层结构。一个重要的目标是最小化由于有限载流子扩散和重组造成的损失。均相掺杂、表面钝化和催化剂层将进一步提高效率。此外，我们将创建电极结构，通过具有不同带边缘位置的材料成分的堆叠层，为快速电荷分离提供额外的驱动力。用于水暗电解的互补金属氧化物纳米形态将具有降低过电位、高可用电流和提高稳定性的特点。这些合成工作将在很大程度上取决于从理论工作和原子尺度表征中获得的见解，其中掺杂对电子结构的影响将被研究。来自理论和电子显微镜的关键见解将反馈到上述设计循环中，以进一步提高光电化学和电化学电池的效率。降解机制也将通过分析电子显微镜来确定，并将制定策略来增加纳米结构的稳定性。

The main goal of this research project is the development of novel metal oxide nanomorphologies for efficient electrochemical and light-driven water splitting. We will pursue a two-pronged search approach that is based on (i) computational screening using high throughput DFT calculations, and (ii) intensive collaborations within the SPP 1613 in the area of high throughput synthesis and testing. Optimized nano-morphologies at different levels of complexity will be developed, including thin film model systems, porous nanostructured films created through templating, and hierarchical structures. An important goal is to minimize losses due to limited carrier diffusion and recombination. Homogeneous doping, surface passivation and catalyst layers will serve to further enhance efficiency. Moreover, we will create electrode structures providing an additional driving force for rapid charge separation by means of stacked layers featuring materials compositions with different band edge positions. Complementary metal oxide nanomorphologies for the dark electrolysis of water will be developed with reduced overpotential, high available currents and improved stability. These synthesis efforts will strongly depend on the insights gained from the theoretical work and atomic scale characterization, where the impact of doping on the electronic structure will be investigated. Key insights from theory and electron microscopy will be fed back into the design loop described above, to further improve the efficiency of the photoelectrochemical and electrochemical cells. Degradation mechanisms will also be identified through analytical electron microscopy and strategies will be developed to increase the stability of the nanostructures.