Photoelectrocatalysis for Terrestrial and Space Applications
ABOUT OUR RESEARCH
Our group is interested in the development, analysis and optimization of earth-abundant, technologically advanced III-V semiconductor-electrocatalyst systems for the photoelectrochemical production of high-valuable chemicals and oxygen. These systems mimic the most important pieces of photosynthesis, nature's go-to solar energy conversion mechanism. Upon photoexcitation, the semiconductor transfers holes or electrons to the integrated electrocatalyst which catalyses the oxidation reaction (e.g., oxygen production) at the (photo-)anode or reduction reaction (hydrogen production, CO2 conversion into long-chain hydrocarbons etc.) at the photocathode. Of particular importance is hereby a careful energetic alignment of the semiconductor-electrocatalyst and the electrocatalyst-electrolyte interface. Furthermore, the electrocatalyst surface composition and topography plays a key role in the catalytic reaction and spectroscopic and optical techniques such as XPS and AFM, HRSEM and HRTEM, resp., are essential tools to investigate catalyst performance and establish routes for its optimization.
Green technologies for Mars and Earth?
The research into artificial photosynthesis and photoelectrocatalysis at ZARM has the potential to be applied not only to space technology, but also to drive advances in energy efficiency and the green energy transition here on Earth. The key lies in the efficient, direct use of solar energy, especially for the production of fuels such as hydrogen. This is important especially as the demand for green fuels grows. As green fuels in turn rely on renewable energy sources, the results of the research at ZARM could help to improve the efficiency of solar energy conversion and storage. As a result, this technology would not only benefit space missions, but also drive the development of environmentally friendly energy systems and the reduction of CO2 emissions on our planet.
Our fields of research
- The development of alternative, passive phase separation systems for gas bubble detachment from electrode surfaces in microgravity (e.g., via electrocatalyst nanostructures or the utilization of magnetically-induced buoyancy).
- The simulation of (photo-)electrochemical devices in microgravity using COMSOL Multiphysics, OpenFOAM and numerical methods, specifically focusing on simulating mass transfer in the electrolyte and gas bubble evolution.
- The (photo-)electrodeposition of metals on (photo-)electrodes in microgravity and the investigation of the impact gravity has on the nucleation and growth of metal layers and the metal nanotopography.
CONTACT
Efficient Solar-Driven Oxygen and Fuel Production Utilizing Magnetically-Induced Buoyancy for Life Support During Long-Term Space Travel
Our reserach groups has together with Prof. Álvaro Romero-Calvo, head of the Low-Gravity Science and Technology Lab at GeorgiaTech (USA), the opportunity to fly our experiments on a Sounding Rocket to the borders of space! The project "Efficient Solar-Driven Oxygen and Fuel Production Utilizing Magnetically-Induced Buoyancy for Life Support During Long-Term Space Travel" was selected by ESA to fly between 2024-2025.
Our team will provide a proof-of-concept microgravity test of an autonomously operating, efficient and monolithic solar water-splitting device for oxygen and hydrogen production which could complement currently existing life support technologies. In order to achieve efficient and stable gas production, we will investigate two key mechanisms to successfully detach hydrogen and oxygen gas bubbles from the electrode surface and direct them through the electrolyte solution to a gas collection point: i) magnetically-induced buoyancy, and (ii) hydrophilic electrocatalyst structures. The longer microgravity time provided by the sounding rocket experiment will be crucial to successfully demonstrate the effect of both mechanisms.
Our results will not only be key for demonstrating the possibility of utilizing photoelectrochemical devices in space which could be extended e.g., to carbon dioxide removal and chemical synthesis – they will also be instrumental in optimizing electrolyzer systems, phase separators, and boiling processes in reduced gravitation.
The list below shows the latest 25 publications of this research group. For the complete, searchable list of ZARM publications, please click more