The First Precise Determination of Graphene Functionalisation by in situ Raman Spectroscopy

Abstract

We report, for the first time, a comprehensive study involving in situ Raman spectroscopy supported by quantum mechanical calculations to exactly monitor the covalent binding to graphene with unprecedented precision. As a model reaction we have chosen the hydrogenation of reduced graphite ($K{C}_8$) with $H_{2}O$ and compared it with the corresponding exposure to $H_2$ and $O_2$. The early stages of graphene hydrogenation are accompanied by the evolution of a series of so far undiscovered D-bands ($D_1$-$D_5$). Using quantum mechanical calculations, we were able to unambiguously assign these bands to distinct lattice vibrations in the neighborhood of the covalently bound addend. Interestingly, the exposure of $K{C}_8$ to $H_2$ and $O_2$ didn't cause covalent binding, but intercalation of molecular $H_2$ or partial oxidation, respectively. A combination of $H_{2}O$ and $O_2$ treatment led to the formation of additional hydroxyl (-OH) functionalities. The latter reaction represents a very suitable model for the decomposition of graphenides under ambient conditions (hydrogenation and hydroxylation). We have applied this Raman analysis to simulate and satisfactorily characterize a series of additional covalently functionalised graphene derivatives prepared as bulk materials with different composition (e.g. degree of functionalisation and the nature of covalent addend) demonstrating the generality of the concept and the fundamental value for graphene chemistry.

34 pages, 14 figures, 1 table

References in corpus (10)

• The Raman Fingerprint of Graphene
• Raman spectroscopy as a versatile tool for studying the properties of graphene
• Quantifying defects in graphene via Raman spectroscopy at different excitation energies
• Electrochemically Top Gated Graphene: Monitoring Dopants by Raman Scattering
• Chemistry with Graphene and Graphene Oxide - Challenges for Synthetic Chemists
• Raman imaging of doping domains in graphene on SiO2
• Manifestation of charged and strained graphene layers in the Raman response of graphite intercalation compounds
• Double- and Single-Sided bis-Functionalization of Graphene
• Basic Insights into Tunable Graphene Hydrogenation
• Polyhydrogenated Graphene - Excited State Dynamics in Photo- and Electroactive 2D-Domains

Cited by in corpus (9)

• Post Graphene 2D Chemistry: The Emerging Field of Molybdenum Disulfide and Black Phosphorus Functionalization
• Nitrogen-doped graphene based triboelectric nanogenerators
• Effect of residual gas composition on epitaxial graphene growth on SiC
• Ab-initio wave-length dependent Raman spectra: Placzek approximation and beyond
• Incidence of multilayers in chemically exfoliated graphene
• Ultralong spin lifetime in light alkali atom doped graphene
• Lattice Opening Upon Bulk Reductive Covalent Functionalization of Black Phosphorus
• Reductive Functionalization of Graphenides with Nickel(II) Porphyrin Diazonium Compounds
• Tuning Conductivity and Spin Dynamics in Few-Layer Graphene via In Situ Potassium Exposure