One-step fabrication of Au-Ag alloys and its application for catalysts and SERS sensors

[Display omitted] •Au-Ag alloy NPs with controllable size and composition were synthesized by a facile, one-pot hydrothermal method.•The size and composition of Au-Ag alloy NPs could be adjusted by the experimental parameters.•Ideal catalytic and SERS performance could be obtained via optimizing the size and composition of Au-Ag alloy NPs. Au-Ag alloy nanoparticles (NPs) with controllable size and composition were synthesized by a facile, one-pot hydrothermal method. Various characterization techniques including TEM, UV–vis, EDX, HAADF-STEM and XPS were used to discuss the influencing factors for the size and composition of Au-Ag alloy NPs. It is obvious that the size and composition of Au-Ag alloy NPs could be adjusted by the experimental parameters. Catalytic and SERS performance of the Au-Ag alloy NPs were further investigated. Ideal catalytic and SERS performance could be also obtained via optimizing the size and composition of Au-Ag alloy. This work is of importance in theory research and practical application of the noble metal nanocomposites.