Abstract
The 2D transition metal carbides or nitrides, or MXenes, are emerging as a group of materials showing great promise in lithium ion batteries and supercapacitors. Until now, characterization and properties of single-layer MXenes have been scarcely reported. Here, using scanning transmission electron microscopy, we determined the atomic structure of freestanding monolayer Ti3C2Tx flakes prepared via the minimally intensive layer delamination method and characterized different point defects that are prevalent in the monolayer flakes. We determine that the Ti vacancy concentration can be controlled by the etchant concentration during preparation. Density function theory-based calculations confirm the defect structures and predict that the defects can influence the surface morphology and termination groups, but do not strongly influence the metallic conductivity. Using devices fabricated from single- and few-layer Ti3C2Tx MXene flakes, the effect of the number of layers in the flake on conductivity has been demonstrated.
Original language | English |
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Pages (from-to) | 9193-9200 |
Number of pages | 8 |
Journal | ACS Nano |
Volume | 10 |
Issue number | 10 |
DOIs | |
State | Published - Oct 25 2016 |
Funding
Research was supported as part of the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. Aberrationcorrected STEM imaging and device fabrication and measurement were conducted at Oak Ridge National Laboratory's Center for Nanophase Materials Sciences (CNMS), a U.S. Department of Energy Office of Science User Facility. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
Funders | Funder number |
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DOE Office of Science | DE-AC02-05CH11231 |
Office of Basic Energy Sciences | |
U.S. Department of Energy Office of Science | |
U.S. Department of Energy | |
Office of Science |
Keywords
- MXene
- conductivity
- defect
- minimally intensive layer delamination (MILD)
- vacancy