Large scale chemical functionalization of graphene with nanometer resolution

TL;DR

This paper introduces a novel method for large-scale chemical functionalization of graphene with nanometer precision by inducing strain through nanoparticle decoration, enabling controlled placement of functional groups.

Contribution

The study demonstrates that strain modulation via nanoparticle decoration allows for nanometer-scale control of chemical functionalization on graphene, a significant advancement over previous microscopy-based methods.

Findings

Functionalization level increases with nanoparticle density.

Strain-induced functionalization is confirmed by Raman, AFM, and XPS.

Method achieves nanometer resolution on a large scale.

Abstract

Anchoring various functional groups to graphene is the most versatile approach for tailoring its functional properties. To date, one must use a special tunneling microscope for attaching a molecule at a specific position on the graphene with resolution better than several hundred nanometers, however, achieving this resolution is impossible on a large scale. We demonstrate for the first time that chemical functionalization can be achieved with nanometer resolution by introducing strain with nanometer scale modulation into a graphene layer. The spatial distribution of the strain has been achieved by transferring a single-layer graphene (SLG) onto a substrate decorated by a few nm large nanoparticles (NPs). By changing the number of NPs on the substrate, the amount of locally strained SLG increases, as confirmed by atomic force microscopy (AFM) and Raman spectroscopy investigations. We further carried out hydrogenation and fluorination on the SLG with increasing amount of nanoscale corrugations. Raman spectroscopy, AFM and X-ray photoelectron spectroscopy revealed unambiguously that the level of functionalization increases proportionally with the number of NPs, which means an increasing number of the locally strained SLG. Our approach thus enables control of the amount and the position of functional groups on graphene with nanometer resolution.