Journal
ACS NANO
Volume 5, Issue 6, Pages 4401-4406Publisher
AMER CHEMICAL SOC
DOI: 10.1021/nn103200t
Keywords
graphene; graphene oxide; electron energy loss spectroscopy (EELS); in situ TEM
Categories
Funding
- International Center for Materials Nanoarchitectonics (MANA) of the National Institute for Materials Science (NIMS), Japan
- NSF [10874218, 50725209, 11004230]
- MOST, China [2007CB936203, 2007AA03Z353]
Ask authors/readers for more resources
A suspended graphene oxide device is fabricated and Investigated using a transmission electron microscope (TEM) scanning tunneling microscope (STM) setup. A detailed study of step-by-step reduction of an individual graphene oxide sheet under current flow and Joule heating in tandem with conductivity measurements, atomic structure imaging, chemical composition, and bonding alternations tracing is performed. As monitored by electron energy loss spectroscopy, the oxygen content Is tuned from that peculiar to a pristine graphene oxide (i.e., 23.8 at %) to oxygen-free pure graphene. Six orders of magnitude conductance rise Is observed during this process. with the final conductivity reaching 1.5 x 10(5) S/m. Quantification of plasma energy losses of the stirring graphene oxide shows that similar to 40% of the oxygen atoms are in the form of epoxy, and similar to 60% oxygen atoms are in the form of hydroxyl. The total portion of sp(3) bonds in pristine graphene oxide is estimated to be similar to 45%. The epoxy groups show a larger Influence on the conductivity of graphene oxide than hydroxyl ones. Through analyzing consecutive plasma-loss energy spectra under gradual graphene oxide to graphene transformation, it is found that the oxygen atoms in epoxy groups decompose prior to those In hydroxyl groups.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available