Covalent Organic Functionalization of Graphene Nanosheets and Reduced Graphene Oxide via 1,3-Dipolar Cycloaddition of Azomethine Ylide

Abstract

Organic functionalization of graphene is successfully performed via 1,3-dipolar cycloaddition of azomethine ylide in the liquid phase. The comparison between 1-methyl-2-pyrrolidinone and N,N-dimethylformamide as dispersant solvents, and between sonication and homogenization as dispersion techniques, proves N,N-dimethylformamide and homogenization as the most effective choice. The functionalization of graphene nanosheets and reduced graphene oxide is confirmed using different techniques. Among them, energy-dispersive X-ray spectroscopy allows to map the pyrrolidine ring of the azomethine ylide on the surface of functionalized graphene, while micro-Raman spectroscopy detects new features arising from the functionalization, which are described in agreement with the power spectrum obtained from ab initio molecular dynamics simulation. Moreover, X-ray photoemission spectroscopy of functionalized graphene allows the quantitative elemental analysis and the estimation of the surface coverage, showing a higher degree of functionalization for reduced graphene oxide. This more reactive behavior originates from the localization of partial charges on its surface due to the presence of oxygen defects, as shown by the simulation of the electrostatic features. Functionalization of graphene using 1,3-dipolar cycloaddition is shown to be a significant step towards the controlled synthesis of graphene-based complex structures and devices at the nanoscale.

15 pages, 8 figures, for associated Supporting Information see http://shorturl.at/dCQ07

References in corpus (11)

• Electric Field Effect in Atomically Thin Carbon Films
• Canonical sampling through velocity-rescaling
• The Raman Fingerprint of Graphene
• Universal Dynamic Conductivity and Quantized Visible Opacity of Suspended Graphene
• Suspended Graphene: a bridge to the Dirac point
• Probing the Nature of Defects in Graphene by Raman Spectroscopy
• Evidence of Klein tunneling in graphene p-n junctions
• Laser-induced disassembly of a graphene single crystal into a nano-crystalline network
• Nitrogen-Functionalized Graphene Nanoflakes (GNFs:N): Tunable Photoluminescence and Electronic Structures
• Covalent functionalization of strained graphene
• Revealing the multi-bonding state between hydrogen and graphene-supported Ti clusters

Cited by in corpus (3)

• Deterministic Covalent Organic Functionalization of Monolayer Graphene with 1,3-Dipolar Cycloaddition Via High Resolution Surface Engineering
• Surface Grafting of Graphene Flakes with Fluorescent Dyes: A Tailored Functionalization Approach
• Three-dimensional graphene on a nano-porous 4H-SiC backbone: a novel material for food sensing applications