TiO2 based Inorganic-Organic Hybrid Photocatalysts for Highly Selective Alcohol Partial Oxidation

An integrated approach to develop a composite hybrid material made of titanium dioxide functionalized with an organic conjugated phenol (DIOL) and silver NPs suitable for the selective oxidation of water soluble aromatic alcohols to aldehydes in water under UV irradiation and very mild conditions was used. The 86% selectivity observed for the Rutile/DIOL/Ag composite is, to the best of our knowledge, the highest thus far reported for partial oxidation of aromatic alcohols to aldehydes in water suspensions of titanium dioxide. The method is general as it relies on the concomitant easier adsorption of the aromatic alcohol and more facile release of the aldehyde, coupled to fast interfacial electron transfer due to the conjugated DIOL acting as a molecular electron bridge covalently bound to both silver NPs and titanium dioxide. Modification of the shuttle molecule as well as utilization of other metal NPs could potentially open the route to optimization of the selective conversion for several other photocatalytic redox reactions mediated by similar advanced titanium dioxide- based composites.