SERS monitoring of methylene blue degradation by Au-Ag@Cu2O-rGO nanocomposite

A combination of multiple materials effectively improves and enhances the performance of the materials. Thus, a gold-silver@cuprous oxide (Au-Ag@Cu 2 O)-reduced graphene oxide (rGO) structure was designed and fabricated. We decorated the Au nanoparticles (NPs) on the Ag@Cu 2 O-rGO composite surface by a redox reaction to form a Au-Ag@Cu 2 O-rGO structure with two noble metals attached to a Cu 2 O semiconductor. A comparable AuAg@Cu 2 O structure was also fabricated. After decorating Au NPs into the Ag@Cu 2 O-rGO composite, the AuAg@Cu 2 O composite structure was loosened, and the surface and interior of the Cu 2 O shell were decorated with Au and Ag NPs. Moreover, the addition of Au NPs resulted in a proper surface plasmon resonance effect and a significant broadening of the absorption range. The loose structure increased the adsorption of the probe molecules, which increased the surface -enhanced Raman scattering (SERS) intensity. In addition, the fabricated AuAg@Cu 2 O-rGO exhibited excellent catalytic reduction of methylene blue (MB) with sodium borohydride (NaBH 4 ). Therefore, the SERS-based monitoring of the MB degradation was obviously improved.