ZnO microrods photodeposited with Au@Ag nanoparticles: Synthesis, characterization and application in SERS

Decorating one-dimensional micromaterials with nanoparticles provides an effective method to manipulate and integrate their physicochemical and optoelectronic properties. Here, we demonstrate an example of photochemical deposition of Au core/Ag shell nanoparticles onto ZnO microrods (ZnO/Au@Ag). The as-prepared micromaterials were characterized and confirmed by UV-vis spectra, XRD, XPS, FE-SEM and EDX analysis. Raman spectra revealed that the vibration energy of oxygen sublattice decreased after deposition of metallic nanoparticles. Their apparent Fermi level was calculated to be 156.9 mV from a Nernstian equilibrium with a redox couple in solution and primary investigation indicated their potential application as an active surface enhanced Raman spectroscopy substrate. The proposed method could extend to synthesize a series of core-shell nanoparticles decorated one-dimensional composite micromaterials and the as-prepared multifunctional micromaterials may also find their application in photocatalysis, gas sensor and so on.