Solid state photocatalysts like semiconductors are often very stable but suffer from problems with selectivity. Molecular catalysts on the other hand can be highly selective and properties can be tuned relatively easy by structural modifications. However, the highly reduced states often needed to be catalytically active are often very unstable leading to low turn over numbers and poor overall efficiencies. Therefore we try to combine the selectivity and tunability of molecules with the stability of semiconductors within this project, with the aim of driving charge transfer reactions through the conduction band of a semiconductor like TiO2. This requires control of the charge injection into the semiconductor as well as precise understanding and control of the release of charges from the conduction band. This leads to the need for use of electrolytes and additives that allow exact tuning of conduction band properties. Among other things we are looking at how environmentally friendly ionic liquids can be used as an electrolyte in this system and how that affects charge injection and recombination processes. In parts of this project we collaborate with Gerrit Boschloo and Anders Hagfeldt at Uppsala University.