Graphene, a two-dimensional (2D) hexagonal arrangement of sp² carbon, is gaining popularity as a material for electrochemical sensors. Graphene outstanding electrical properties has led researchers to develop three-dimensional (3D) atomic layer graphene materials with increased surface area as more efficient electrodes. Although 3D graphene materials such as foams and multilayered carbon nanowalls have already been synthesized, synthesis of 3D vertical atomic layer graphene still remains a challenge.

Here we demonstrate a novel synthesis of high density single to few layer vertical graphene on semiconductor nanowire mesh templates. The presence of graphene on the nanowires was confirmed by Raman spectroscopy. The progression of the templated growth of the 3D graphene flakes was verified by using scanning electron microscopy. Moreover, the growth of single to few layer crystalline graphene flakes that are vertically orientated with respect to the nanowire axis was validated by transmission electron microscopy. The sheet resistance of the new hybrid nanomaterial decreased with an increase in graphene flake size and density. Lastly, high electrochemically active surface area of the material was ascertained by cyclic voltammetry. These results pave way for the use of 3D vertical atomic layer graphene on nanowire mesh templates as electrodes for electrochemical sensing of biomolecules, quantification of fast-electron transfer reactions, and energy harvesting in fuel cells.