The project focuses on the photoelectrochemical (PEC) conversion of carbon dioxide to useful products. We vigorously studied the effect of size, morphology, and surface functional groups of the photoelectrodes at the nanoscale. As a first step, we designed model systems to deconvolute the effect of the three main processes (light absorption, charge carrier transport and charge transfer), which dictate the solar-to-fuel conversion efficiency in a PEC cell. We studied bimetallic oxides, metal halide, lead halide perovskites in this vein. As the next step, we assembled hybrid photoelectrodes, where different components are responsible for the different processes. For example, nanocarbon-containing photoelectrodes outperformed their bare SC counterpart, due to enhanced charge carrier transport. We have developed and adapted different in situ electrochemical methods, to better understand the light-induced processes both inside the SC photoelectrodes, as well as at the SC/electrolyte interface. Finally, we designed, prepared and studied PEC flow cells to achieve unprecedentedly high CO2 conversion efficiencies). For example, a concentrated photovoltaic cell has been integrated into a custom-made heat managed photo-electrochemical device. With solar concentrations, the solar-to-CO conversion efficiency reaches 17% while maintaining a current density of 150 mA cm-2 in the electrolyzer and a CO selectivity above 90%, representing an overall 19% solar-to-fuel conversion efficiency. We have published over 31 high impact papers so far, in internationally leading journals. In addition, the group members gave dozens of presentations on leading international conferences, to disseminate the results. As for exploitation, an ERC proof of concept grant on this topic was awarded and successfully completed. We were also able to strengthen our ties with the relevant industrial actors, and new technology development orientated projects have span out from the ERC project.
