Selective-Area Fluorination of Graphene with Fluoropolymer and Laser Irradiation

Abstract

We have devised a method to selectively fluorinate graphene by irradiating fluoropolymer-covered graphene with a laser. This fluoropolymer produces active fluorine radicals under laser irradiation that react with graphene but only in the laser-irradiated region. The kinetics of C-F bond formation is dependent on both the laser power and fluoropolymer thickness, proving that fluorination occurs by the decomposition of the fluoropolymer. Fluorination leads to a dramatic increase in the resistance of the graphene while the basic skeletal structure of the carbon bonding network is maintained. Considering the simplicity of the fluorination process and that it allows patterning with a nontoxic fluoropolymer as a solid source, this method could find application to generate fluorinated graphene in graphene-based electronic devices such as for the electrical isolation of graphene.

Two‐Dimensional Fluorinated Graphene: Synthesis, Structures, Properties and Applications

“…Fluorination mainly include direct gas‐fluorination,[[qv: 4a]],[[qv: 12a]],[[qv: 13b]],[[qv: 21a]],22 plasma fluorination,23 hydrothermal fluorination,24 and photochemical/electrochemical synthesis 25. Exfoliation methods includes sonochemical exfoliation,[[qv: 9a]],26 modified Hummer's exfoliation,20,[[qv: 21b]] and thermal exfoliation 27.…”

Photochemistry of Graphene

“…In particular, F · and Cl · are very reactive and can easily break -C¼C-bonds. For example, F · can functionalize graphene in a very short time once generated and achieve stoichiometric fluorographene (C/F ratio 1:1) ultimately [82,94,104,105]. In order to slow down the reaction and get better controllability, F · has to be generated via fluorination agents, such as XeF 2 and fluoropolymers, from which F · can be mildly released [94].…”

“…In order to slow down the reaction and get better controllability, F · has to be generated via fluorination agents, such as XeF 2 and fluoropolymers, from which F · can be mildly released [94]. Recently, a facile photochemical approach has been developed to obtain fluorographene by laser irradiating fluoropolymer-covered graphene, in which the fluoropolymer molecules can release F · under the irradiation and functionalize graphene ultimately [104]. The photochlorination of graphene was inspired by the chlorine addition reaction of benzene in the presence of light [106].…”

Nanoscale assembly into extended and continuous structures and hybrid materials

“…Recent advances in the patterned or complete fluorination of graphene allow the electronic properties and solubility of the carbon framework to be tailored, giving rise to insulating sheets a single carbon layer thick for use as interlayers in electronic applications. 88,89 Graphene modification and processing The most common method for preparing soluble, functionalizable graphene derivatives is the preparation of individual sheets of graphene oxide (GO) by the treatment of insoluble graphite (that is, aggregated graphene platelets) with strong acid. GO has a disrupted p-system (similar to acid-treated carbon nanotubes), a crumpled carbon framework bearing hydroxyl and epoxide groups on sp 3 hybridized carbon atoms within the sheet, carboxylates along the edges, and a C:O ratio of B2:1 (Figure 6b).…”