Angew. Chem. Int. Edn doi:10.1002/anie.201003110 (2010)

The ability to split water into hydrogen and oxygen could be an important step in the development of renewable fuels. The use of haematite, a form of iron oxide, as an electrode to drive this reaction with the help of light is well established. This material is stable in water and can be made from low-cost abundant elements. However, it has not been as effective as titanium or tungsten oxide electrodes.

Now Kevin Sivula, Michael Grätzel and their colleagues at the Swiss Federal Institute of Technology (EPFL) in Lausanne have made two alterations to boost haematite's water-splitting ability.

They altered the compound's nanostructure to improve its electronic properties and deposited nanoparticles of iridium oxide — a water oxidation catalyst — on its surface. The performance achieved is not at a commercially useful level, but is superior to that previously described for other oxide-based materials.