Impact of Decoration Method on Some Physical Properties of Ag@Cu₂O Nanostructure

Ag-decorated cuprous oxide was synthesized by hydrothermal method by mixing and spraying AgNO₃ with copper nanopowder and deionized water. X-ray diffraction shows that the formation of Cu₂O and Ag, the particle size was determined to be 27.3 nm and 31.4 nm, besides strain and dislocation density was determined. Two absorption peaks were observed at 350 and 530 nm and 385 and 538 nm for two samples, respectively; one of them belongs to the plasmon effect and the other due to the formation of cuprous oxide. Bandgap energy was estimated from the absorption spectra to be 2.1 eV and 2 eV. Different shapes, such as truncated octahedrons, branches, and microflowers, were formed. The elemental composition of the two samples shows the presence of Cu, O, and Ag at different intensities based on the decoration procedure. The results indicated a significant enhancement in Raman signal intensity. The improvement for the sample in which silver and copper were mixed was a little more attributed to the presence of Ag which is known for its surface-enhanced Raman scattering (SERS) capabilities.