Shape Selective Au-TiO2 Nanocomposites for Photocatalytic Applications

Au-TiO2 nanocomposites having different assemblies (Aucylindrical nanorods-TiO2, Au hexagonal nanoprisms-TiO2 and Au trigonal nanoprisms-TiO2) were successfully synthesized using the controlled hydrolysis of the titanium precursor, titanium diisopropoxidebis(acetylacetonate) along with the appropriate Au nanostructures. The morphology analysis was done using high resolution transmission electron microscope (HRTEM) and other relevant techniques. Interestingly, the novel assemblies showed better photocatalytic activities as compared to the other reported photocatalysts based on Au-TiO2 which was illustrated by the oxidative conversion of methanol into formaldehyde, detected quantitatively by the Nash method. The enhanced photo catalytic performance was compared to TiO2 nanoparticles without Au nanostructures and it was ascribed that the charge separation of photo generated electrons and holes at the Au-TiO2 interface was facilitated by the close proximity of the gold nanoparticles. Furthermore, we also examined the photo catalytic activity of the nanocomposites under UV light for the degradation of methanol to formaldehyde and it was proven that the novel assemblies of Au-TiO2 can work under UV light, which can have direct practical implications. (C) 2015Elsevier Ltd. All rights reserved.