Gold nanoparticle - modified zinc oxide nanoparticles as novel photocatalytic materials.

摘要

The current study entails the construction of a novel nano-composite catalyst based on ZnO and Au nanoparticles and demonstrates its distinctive photocatalytic characteristics. Monodisperse gold nanoparticles (GNPs) passivated with monolayers of tiopronin or glutathione were synthesized via facile methods, and they were assembled on ZnO nanoparticles to form the nano-catalyst.;Steady state and time resolved photoluminescent studies on the nano-composite revealed interesting charge transfer characteristics within the nano- composite. Enhanced photooxidation of rhodamine 6G was observed for the nano-composite over bare ZnO, and modulation of photoactivity with the extent of GNP loading was illustrated. Photoreduction of thionine over the nano- composite was found to have similar characteristics.;Significance of band edge energies of the semiconductor and the ability of GNPs to modulate them, consequently affecting the photocatalytic properties of nano-composite is discussed. Calcination, applied as a post-synthesis treatment method was found to be detrimental for the photocatalytic activity of nano- composites. Preliminary experiments suggested the potential of these nano- composites to be used as effective photocatalysts in treating environmentally significant pollutants such as pesticides.