Rapid and direct conversion of graphite crystals into high-yielding, good-quality graphene by supercritical fluid exfoliation.
Graphene has attracted a great deal of attention in recent years due to its unusual electronic, mechanical, and thermal properties. Exploiting graphene properties in a variety of applications requires a chemical approach for the large-scale production of high-quality, processable graphene sheets (GS), which has remained an unanswered challenge. Herein, we report a rapid one-pot supercritical fluid (SCF) exfoliation process for the production of high-quality, large-scale, and processable graphene for technological applications. Direct high-yield conversion of graphite crystals to GS is possible under SCF conditions because of the high diffusivity and solvating power of SCFs, such as ethanol, N-methyl-pyrrolidone (NMP), and DMF. For the first time, we report a one-pot direct conversion of graphite crystals to a high yield of graphene sheets in which about 90-95% of the exfoliated sheets are < 8 layers with approximately 6-10% monolayers and the remaining 5-10% are > or = 10 layers.
Rangappa
Dinesh
D
National Institute of Advanced Industrial Science and Technology, Umezono 1-1-1, Tsukuba, Ibaraki 305-8568, Japan. dinesh.r@aist.go.jp
Sone
Koji
K
Wang
Mingsheng
M
Gautam
Ujjal K
UK
Golberg
Dmitri
D
Itoh
Hiroshi
H
Ichihara
Masaki
M
Honma
Itaru
I