ERC Project

Solid-liquid interface

Since Fujishima and Honda published in 1972 that hydrogen can be produced by photocatalytic splitting of water on a titanium dioxide (TiO2) electrode, it is one of the most promising energy carriers. The energy of the sun is stored in chemical energy. Since 1972 a lot of research has been performed aiming at improving the efficiency of the process. Our research focus is on unravelling the mechanism of the dissociation reaction at the interface at the molecular level. In the first part of the project we are determining the structure and orientation of water at the TiO2 interface by applying the sum-frequency generation techniques. As the surface of titanium dioxide seems to be complex and not straightforward to characterize, it is necessary to understand the vibrational SFG response of water at such surfaces on a fundamental level. With silica and calcium fluoride, we are studying two mineral surfaces which serve as useful model systems and also provide scientific input for how to access physical surface properties such as surface potential, surface charge density and Debye screening length by using SFG. Additionally, we can deduce how water binds to such surfaces and its intermolecular structure differs from layers further away.

The filmed presentation of this project at the World Economics Forum can be found here:
http://www.mpip-mainz.mpg.de/Backus_Weltwirtschaftsforum