Photoluminescence (PL) Quenching and Enhanced Photocatalytic Activity of Au-Decorated ZnO Nanorods Fabricated through Microwave-Assisted Chemical Synthesis

ZnO nanorods decorated with gold nanoparticles of ~20 nm average size were fabricated by microwave-assisted chemical synthesis. For the surface-attached growth of metal nanoparticles, the ZnO nanostructures were first functionalized by sodium citrate and then the metal ions were reduced under microwave heating. While the incorporation of gold nanoparticles at the surface seen to quench both the band edge and visible emissions of the ZnO nanostructures, it enhances the degradation rate of Rhodamine 6G up to 3 folds under UV emission. The mechanisms of citrate functionalization, growth of Au nanoparticles on the surface of the oxide nanostructures, luminescence emission quenching, and enhanced photocatalytic activity of the composite nanostructures have been discussed.