Issue 31, 2018

Interplay of non-uniform charge distribution on the electrochemical modification of graphene

Abstract

Graphene is considered a model material for surfaces because it is stable despite being composed of a single layer of carbon atoms. Although the thermal and electronic properties of graphene are well reported, the behavior of graphene sheets with the addition of charges to the structure is not well understood. Combining infrared spectroscopy, electrochemical analysis, and computational simulations, we report the effect of an electrochemically induced covalent anchoring of 4-carboxyphenyl (4-CP) units on the optical and electronic properties of graphene. Charges in graphene become concentrated at specific sites of the sheet when electrochemically perturbed and the functionalization occurs inhomogeneously along the graphene sheet. We observed that, when graphene is covalently functionalized, the resistance to heterogeneous electron transfer is increased by a factor of 1.4. Furthermore, scattering-type scanning near-field optical microscopy and atomic force microscopy show that the covalent functionalization affects drastically the optical and physical properties of the graphene/SiO2 system, especially the plasmon–phonon coupling after the functionalization. In addition, from these we infer that a comparatively higher degree of functionalization occurs near the electrode edges. These results are supported by computational simulations, which show that the covalent anchoring of 4-CP units weakens electron transfer because the charges are retained on the sp3-hybridized carbon atoms generated upon functionalization, suggesting that graphene properties are deeply influenced by the way the molecules are immobilized on its structure.

Graphical abstract: Interplay of non-uniform charge distribution on the electrochemical modification of graphene

Supplementary files

Article information

Article type
Paper
Submitted
14 5月 2018
Accepted
23 7月 2018
First published
24 7月 2018

Nanoscale, 2018,10, 15048-15057

Interplay of non-uniform charge distribution on the electrochemical modification of graphene

L. J. A. Macedo, F. C. D. A. Lima, R. G. Amorim, R. O. Freitas, A. Yadav, R. M. Iost, K. Balasubramanian and F. N. Crespilho, Nanoscale, 2018, 10, 15048 DOI: 10.1039/C8NR03893G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements