Final Report Summary - WATIO (Water on TiO2)
Fossil fuels are present in limited amounts on earth and produce green house gases by their combustion. A very promising, environmentally-friendly alternative energy source is hydrogen. Hydrogen can be produced photocatalytically from water on a titanium dioxide (TiO2) electrode. Since the discovery of the hydrogen production under the influence of light, much research has been performed to make the process more efficient. As this optimization is mostly performed through a trial-and-error approach, fundamental knowledge of the process has been lacking up to now. The aim of the research performed with the Marie Curie Career Integration Grant was to obtain fundamental knowledge of the process by looking at specifically the molecules at the interface, before, during and after their dissociation. We proposed to study how water is bound to the catalyst, what the relation between structure and reactivity is, and what the dynamics of the photodissociation reaction are. We used the surface sensitive technique sum-frequency generation (SFG) to obtain information about the molecules at the water-TiO2 interface. In the first year of the project we learned how to make clean TiO2 interfaces, characterized them, and did some first SFG studies on the samples.