Synthesis of functionalized few layer graphene via electrochemical expansion

Single layer graphene is a nearly transparent two-dimensional honeycomb sp2 hybridized carbon lattice, and has received immense attention for its potential application in next-generation electronic devices, composite materials, and energy storage devices. This attention is a result of its desirable and intriguing electrical, mechanical, and chemical properties. However, mass production of high-quality, solution-processable graphene via a simple low-cost method remains a major challenge. Recently, electrochemical exfoliation of graphite has attracted attention as an easy, fast, and environmentally friendly approach to the production of high-quality graphene. This route solution phase approach complements the original micromechanical cleavage production of high quality graphite samples and also involved a chemically activated intermediate state that facilitates functionalization. In this thesis we demonstrate a highly efficient electrochemical exfoliation of graphite in organic solvent containing tetraalkylammonium salts, avoiding oxidation of graphene and the associated defect generation encountered with the broadly used Hummer's method. The expansion and charging of the graphite by intercalation of cations facilitates the functionalization of the graphene basal surfaces. Electrochemically enhanced diazonium functionalization of the expanded graphite was performed. The exfoliated graphene platelets were analyzed by Raman spectroscopy, to quantify defect states and the degree of exfoliation. Additional microscopy techniques provided additional insight into the chemical state and structure of the graphene sheets.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Materials Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2015

Author dc:creator

• Jeon, Intak

Advisor dc:contributor.advisor

• Timothy M. Swager.

• Materials Science and Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/101797

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/101797