▎ 摘　　要

The growth of graphene-based nanostructures using chemical vapor deposition (CVD) is a promising approach for novel applications. CVD processes typically use high-quality metal films as catalyst substrates, and require accurate control over the experimental conditions. Here, we report the direct synthesis of Ni nanosheet/graphene composites using a DC arc plasma jet CVD method, using Ni(NO3)(2) as a catalyst precursor. The composites consisted of graphene nanosheets, graphene nanoribbons, and core-shell Ni/graphene nanosheets. In this process, no catalyst substrate was required, and the very high-quality graphene grew at the {111} plane of the Ni. It was demonstrated that the Ni nanosheet/graphene composites could be used as sensitive films for L-alanine sensing. The strong electrocatalytic properties resulted from the synergetic effects of the graphene, which enhanced the electron transfer, and the high catalytic activity of the Ni. (C) 2014 Elsevier Ltd. All rights reserved.