Project Title: Electronic excitations at solid-liquid interfaces: combining many-body perturbation theory with molecular dynamics simulations
Supervisors: Dr Johannes Lischner, Dr Paul Tangney
A major challenge within the energy transformation towards sustainable and renewable energy sources is the energy storage. One potential solution is to store chemical energy in the form of H2 obtained by photoelectrolytic water splitting (PWS) . Current photoelectrolytic water splitting cells (PWSC) are not working eciently enough to be industrially feasible yet. Their eciencies largely depend on the electronic structure of the photoelectrodes, in particular on their electronic band edges. The latter need to be correctly positioned relative to the redox potentials of water to ensure that PWS is thermodynamically possible. Thus, it is essential to be able to precisely predict the valence band maximum and the conduction band minimum of photoelectrodes in an aqueous environment. In this project, many-body perturbation theory within the GW approximation will be used to accurately calculate the electronic structure of the bulk photoelectrodes [2, 3, 4]. Molecular dynamics and joint density-functional theory (JDFT) [5, 6] will be employed to reference the obtained energy levels with respect to the redox potentials in water. Once the methods have been tested on titania (TiO2), other compounds, e.g. CuFeO2 , which are promising photoelectrode materials will be studied. It will be attempted to understand the limitations and shortcomings of current photocatalysts and, based on these insights, attempt to suggests better materials for improved devices.