▎ 摘　　要

Novel three-dimensional Ni@graphene-Cu composites were synthesized by a facile calcination method for the first time. The in-situ generated graphene played an important role in the successful fabrication of Ni@ graphene-Cu that it acted both as an effective reductant to achieve the conversion of CuO to Cu nanopartides (NPs) and as an ideal support to prevent the agglomeration of Cu NPs. The as-prepared Ni@graphene-Cu showed excellent catalytic activity for Cr(VI) reduction to Cr(III) at room temperature with formic acid as reductants. (C) 2015 Elsevier B.V. All rights reserved.