Graphene sheets (GS) supported monometal (Ni, Co) or bimetal (Ni-Co) nanoparticle composites have been conveniently prepared with the assistance of dielectric barrier discharge (DBD) plasma at low temperature. Both graphene oxide and the metal ions (Ni2+, Co2+) can be simultaneously reduced during the DBD plasma treatment in H-2 atmosphere, which gives rise to the uniformly distributed metal nanopartides on the surface of GS. The graphene-based catalysts are used in the catalytic hydrodesulfurization (HDS) of carbonyl sulfide (COS). It is revealed that the bimetallic Ni-Co/GS catalyst exhibits outstanding performance for higher COS conversion compared with the monometal catalysts, suggesting the synergetic effect between Ni and Co active species in the HDS reaction. The presented strategy demonstrates a new pathway for the preparation of graphene-based catalysts with high HDS catalytic performance. (C) 2015 Elsevier B.V. All rights reserved.