Enhanced optical properties of ZnO nanorods decorated with gold nanoparticles for self cleaning surface enhanced Raman applications

Raman is a very useful tool to identify chemical substances. However, Raman signal is normally not very strong and hence it is important to fabricate surface enhance Raman scattering (SERS) substrates of good repeatability and high enhancement factor. In this study, ZnO nanorods were prepared by a facile hydrothermal process assisted with galvanic effect. Gold nanoparticles were decorated on the as-prepared nanorods by sputtering method. The results showed that the Au nanoparticles enhance photoluminescence, Raman scattering and photocatalyst properties of ZnO nanorods. The ZnO@Au based SERS substrate showed high enhancement factor and can detect methylene blue at low concentration of 10(-9) M. In combination with self cleaning under UV irradiation, the ZnO@Au SERS substrates can be reusable and hence it is promising for quantitative analyzing based on Raman scattering.