▎ 摘　　要

Graphene based copper-nickel bimetal nanocomposite (Cu3Ni2-rGO) was prepared via a one-step solvothermal procedure, in which Ni(OH)(2) and Cu(OH)(2) were used as precursors. Structural characterization confirms that the as-prepared Cu3Ni2-rGO nanocomposite is composed of Cu3Ni2 nanoparticles in the size range of 20-100 nm and the reduced graphene oxide (rGO) sheets. Benefiting from the combination of Cu3Ni2 and rGO, the Cu3Ni2-rGO nanocomposite exhibits excellent catalytic performance on reducing highly toxic Cr(VI) at room temperature. The reduction of Cr(VI) (40 mL, 100 mg L-1) can be completed within 6 min using Cu3Ni2-rGO nanocomposite as the catalyst, which is much more efficient than using monometallic nanocomposite containing only Cu or Ni. Moreover, Cu3Ni2-rGO nanocomposite can be magnetically separated, which enables effective recycle. Besides, Cu3Ni2-rGO shows good cycling stability.