Synthesis of ultra-large graphene oxide sheets

摘要

Ultra-large graphene oxide (UL-GO) sheets are formed using a Langmuir-Blodgett (LB) thin film process. Sulfuric acid and nitric acid are applied to interlayers of natural graphite flake to form graphite intercalation compound (GIC) powders. The GIC powders are expanded at a high temperature, and intercalating agents are used to further oxidize the expanded GIC powders by to exfoliating the EG into monolayer graphene oxide (GO) sheets. The GO is sequentially centrifuged and UL-GO sheets are collected. An LB thin film is prepared from the collected sheets and the thin films are reduced and chemically doped.

主权项

1. A method for forming graphene thin films, the method comprising:
pre-intercalating of sulfuric acid and nitric acid to interlayers of natural graphite flake to form graphite intercalation compound powders; expanding of graphite intercalation compound powders at a high temperature; further oxidizing using intercalating agents to exfoliate EG into monolayer graphene oxide sheets; sequential centrifuging of graphene oxide and using the sequential centrifuging to collect graphene oxide as monolayer graphene oxide sheets with a mean lateral size in the range of 50-200 μm; preparing of Langmuir-Blodgett thin films comprised of plural monolayer graphene oxide sheets; and reducing and chemical doping, with —Cl or —SOCl2 groups, to form doped Langmuir-Blodgett thin films.