Photostimulated reduction processes in a titania hybrid metal-organic framework.

Titanium dioxide is the most widely studied photocatalytic metal oxide system, owing largely to the facile chemical reduction of Ti to Ti, which can act as catalytic redox centres, and the early demonstration of its ability to dissociate water into gaseous hydrogen and oxygen under ultraviolet (UV) illumination. Tailoring of the electronic properties of TiO2 is generally performed by chemical doping or alloying, or through the absorption of organic moieties on the surface, as in dye-sensitized solar cells. 7] The formation of hybrid inorganic–organic solids, containing metal oxide networks of reduced dimensionality, offers a new pathway for material functionalization including chemical engineering of optoelectronic properties. Synthesis of a photoactive hybrid solid derived from titania was recently reported by Dan-Hardi et al. : the porous structure is composed of octameric rings of Ti!O polyhedra connected by aromatic dicarboxylate linkers, as shown in Figure 1. While the large internal surface area (1550 m2g!1) offers poten-