▎ 摘　　要

An aqueous based, room temperature, and surfactant-free synthetic route is reported to yield high density of mono-dispersed Ag nanoparticles (AgNPs) supported on graphene oxide (GO) nanosheets. The retaining of oxygen functionalities on GO structure during the redox reaction offers GO the dual role of effective capping and supporting agents to realize the excellent dispersity and stability of the Ag/GO nanocomposites in aqueous solutions. Besides, the size and density of AgNPs anchored on GO are also modulated by controlling the GO, hydrazine, and Ag+ ions at the proper amounts in the growth solution. The combination of high density, pristine surface and the synergistic effect endow the Ag/GO nanocomposites highly catalytic activity towards the reduction of methylene blue (MB) and methyl orange (MO). This rapid, clean, and straightforward procedure offers an attractive avenue for the facile synthesis of noble metallic nanocomposites based on graphene oxides as both stabilizing and supporting materials.