▎ 摘　　要

A new ionic liquid (IL), 1-butyl-3-methylimidazolium cholate, was first synthesized through an ion exchange reaction of 1-butyl-3-methylimidazolium chloride with sodium cholate. Stable aqueous dispersions of graphene were achieved by exfoliating graphite in the presence of the IL under ultrasonication. Both transmission electron microscopy and Raman measurements showed that the IL-stabilized graphene (IL-G) sheets existed with only a few (<5) layers. Furthermore, the IL-G was used to immobilize noble metal nanoparticles (Pt, Pd, Ru, Rh, etc), and a series of graphene-metal (G-M) composites with metal size