Computer modelling of metal oxide semiconductors for photo-catalysis

Due to the depletion of fossil fuels and the intensification of environmental pollution, the need to find alternative and sustainable energy sources is increasing. Since metal oxide semiconductors such as NaNbO3, LaMnO3 and WO3, have the ability to split water photo-catalytically into molecular hydrogen and oxygen, they have become a topic of intense current research. However, the oxidation of the surfaces of the photo-catalysts is an undesired side-effect. Although many reaction mechanisms are not yet fully understood, carefully designed materials containing dopants may well be more stable and retain their catalytic activity.
In this computational project, the fundamental steps to be investigated include:
1. Study of the mixing thermodynamics of the solid-state solution formed between metal oxide semiconductors of known compositions.
2. Incorporation of additional dopants, defects and chiral ligands into the bulk and at the interfaces of the solid-state solutions with the most stable composition and atomic distribution.
3. Evaluation of potential segregation of the dopants, e.g. migration towards the bulk or interfaces.
4. Creation of surface defects, such as vacancies, steps and (hydr-)oxo species upon interaction with environmental molecules.
5. Control of the visible-light photocatalytic activity via tuning of the type and concentration of dopants, chiral ligands, vacancies as well as surface defects and hetero-interfaces.
6. Simulation of the mechanistic pathways for the photo-catalytic water splitting and carbon dioxide conversion into small organic molecules.
7. Development of a machine-learning algorithm to predict new metal oxide semiconductors with larger activities in the presence of visible light.