Fabrication of Graphene Nanomesh and Improved Chemical Enhancement for Raman Spectroscopy

We propose a new approach to fabricate the graphene nanomesh through the local catalytic hydrogenation of carbon by Cu nanoparticles. It allows to tune the size and density of the holes in the nanomesh as well as the total edge length of the holes through the control of the thickness of the Cu film. The upshift of both G and 2D peaks in Raman spectra of the graphene nanomeshes indicates that the nanomesh is spontaneously p-type doped. Moreover, the split of G peak reveals that the doping is localized near the edge region of the hole in the nanomesh. Importantly, the nanomesh shows improved chemical enhancement for Raman spectra of absorbed RhB molecules as compared to the graphene. The edges in the nanomesh can enhance Raman spectroscopy via increasing both the local charge transfer and the ability to absorb RhB molecules. The results show that the graphene nanomesh has a great potential for the rapid and sensitive detection for the environmental monitoring and food security.