Differing photo-oxidation mechanisms: electron transfer in TiO2 versus iron-doped TiO2.

Low-level iron doping has been found to alter the photo-oxidation mechanism of TiO(2) by efficiently activating molecular oxygen. In the absence of iron, TiO(2) either reduces water or stores the electron. Quantitatively, 0.

Water: a responsive small molecule.

Unique among small molecules, water forms a nearly tetrahedral yet flexible hydrogen-bond network. In addition to its flexibility, this network is dynamic: bonds are formed or broken on a picosecond time scale. These unique features make probing the local structure of water challenging.