Our aim is to build atomic-scale models for the structures of some new materials that have useful properties for photocatalytic water splitting, an important contemporary area for producing clean fuels for energy production. In particular we will use the unique capabilities of neutron scattering to resolve structures that show some degree of disorder in their atomic arrangement. Our materials are prepared using soft chemical methods, which allows unusual combinations of chemical elements to be brought together with favourable properties. This provides materials that cannot be made using conventional methods, and in fact upon heating the photocatalysts lose their activity; these samples will also be studied to understand their deactivation. Our experiments will reveal why the materials have favourable properties and in doing so we can optimise the preparation of future materials.