▎ 摘　　要

Using graphene oxide (GO) as both a reducing agent and a support, a two-step method was used to fabricate GO decorated with Au-Ag alloy nanoparticles with an Au-rich shell. The material exhibited excellent catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol in water at room temperature and its activity was superior to that of GO decorated with Au-Ag alloy nanoparticles that was prepared by a one-step method and GO decorated with either Au or Ag nanoparticles alone.