Fabrication of ZnO nanorods decorated Au nanoparticles by hydrothermal and magnetron sputter techniques

In this study, ZnO nanorods decorated with gold (Au) nanoparticles with the desired size parameters were fabricated using a simple, low-cost, and highly efficient method. The ZnO nanorod structure was fabricated using a hydrothermal method on a ZnO seed layer with hydrothermal solution concentrations varying from 20 mM to 90 mM. Au nanoparticles were coated on the ZnO nanorod structure by magnetron sputtering with a sputtering time from the 40s to 70 s. The characteristics of the fabricated samples were investigated through SEM images and optical absorption spectroscopy. The results show that the fabricated ZnO nanorods are relatively uniform, with a cylindrical shape and hexagonal cross-section when the solution concentration is less than 70 mM. Au nanoparticles were attached to the surface of the ZnO nanorods with average sizes of 30-50 nm. The optical absorption spectroscopy results showed that the ZnO nanorods’ absorption edge appeared at a wavelength of approximately 395 nm. In addition, the exciton absorption peak of Au nanoparticles was between 550 nm and 600 nm and there was a shift towards shorter wavelengths as the size of the Au nanoparticle decreased. This result opens up potential applications of this material such as increasing photocatalytic efficiency and its, use in photonic devices, etc.