Human space exploration has to assign uttermost priority to the sustainable fabrication and recycling of materials as a resupply of resources from Earth will not be possible. Moreover, the long-term missions to Moon and Mars will require the use of in-situ resource utilization technologies to synthesise materials in harsh environments and reduced gravitation. This opens a path for research on the fabrication and synthesis of materials in these environments which can e.g., be utilised in energy conversion technologies.
Photoelectrochemical (PEC) energy conversion is currently investigated for space applications as the monolithic design of PEC devices - comprising integrated semiconductor-electrocatalyst systems which utilise water and carbon dioxide for simultaneous oxygen and fuel production - offer significant advantages for long-term space missions such as a compact and lightweight design. This project aims at utilising microgravity environment for the fabrication of nanostructured electrocatalyst materials directly on the semiconductor surface via photodeposition, a sustainable process where sunlight can be the sole source of energy for nanoparticle growth from chemical precursors. As microgravity can lead to particle complexes with high surface to bulk ratios and high crystallinity which improve the overall catalytic properties, the aim of this project is to investigate micro- and reduced gravitation for the fabrication of electrocatalyst materials in greater detail. The resulting nanocatalysts will be tested at the Bremen Drop Tower and GraviTower against their counterparts fabricated terrestrially. The overarching project aim is to obtain a fundamental understanding of catalyst growth and functionality in reduced gravitational environments and to pave the way for synthesising nanomaterials in space, thus reducing the need for supplies from Earth and contributing to an increased sustainability in future space missions.
