2015 US-EU Workshop on 2D Layered Materials and Devices
Two-Dimensional Carbides and Nitrides of
Transition Metals the Largest Family of 2D Materials?
Yury Gogotsi
Director, A.J. Drexel Nanomaterials Institute
Distinguished University and Trustee Chair Professor
Department of Materials Science & Engineering
Drexel University, Philadelphia, PA
April 23, 2015
Background| MN+1AXN (MAX) Phases
M: Early Transition Metal A:
A Group A Element X:
M
X C and/or N
C N
Al Si P S
Sc Ti V Cr Mn
Ga Ge As
Zr Nb Mo
Cd In Sn
Tl Pb
Hf Ta
211
Ti2AlC
Cr2GeC
312
Ti3SiC2
Ti3AlC2
413
Ti4AlN3
Nb4AlC3
IIIA
IVA
Ti2AlC
V2AlC
Cr2AlC
Al Nb2AlC
Ta2AlC
Ti2AlN
Ti3AlC2
V3AlC2
Ta3AlC2
Ti4AlN3
Nb4AlC3
V4AlC3
Ta4AlC3
Ti2GaC Ti2GaN
V2GaC Cr2GaN
Cr2GaC V2GaN
Ga
Nb2Ga
Ti4GaC3
C
Mo2Ga
C
Ta2GaC
In Sc2InC
Ti2InC
Zr2InC
Nb2InC
Hf2InC
Ti InN
Tl 2
Ti2TlC
Zr2TlC
Hf2TlC
Zr2TlN
211
M.W. Barsoum, in Nanomaterials Handbook (ed. Y. Gogotsi), CRC Press (2006)
312
VA
VIA
Ti2SC
Ti
SiC
V
PC
Zr
2SC
S
Si 3 2 P 2
Ti4SiC3
Nb2PC
Nb2SC
Hf2SC
Ge
Ti2GeC
V2GeC
Cr2GeC
Ti3GeC2
Ti4GeC3
Sn Ti2SnC
Zr2SnC
Nb2SnC
Hf2SnC
Hf2SnN
Ti SnC2
Pb 3
Ti2PbC
Zr2PbC
Hf2PbC
413
As
V2AsC
Nb2As
C
From MN+1AXN (MAX) Phases to MXenes
MN+1AXN + 3HF = MN+1XN + AF3 + 3/2 H2
M: Early Transition Metal A:
A Group A Element X:
M
X C and/or N
C N
Al Si P S
Sc Ti V Cr Mn
Zr Nb Mo
Ga Ge As
Cd In Sn
Tl Pb
Hf Ta
Sc
Ti
Zr
Hf
V
Nb
Ta
Cr
MXenes
Ti2C
V2C
Nb2C
(TiNb)2C
Ti3C2
(VCr)3C2
Mo
Ta4C3
Nb4C3
(TiV)3C2
Ti3(C.5N.5)
Mn
IIIA
IVA
Ti 2AlC
V
V2AlC
Cr2AlC
Cr
Nb 2AlC
Al Nb
Ta
Ta 2AlC
Ti2AlN
Ti3AlC2
V3AlC2
Ta3AlC2
Ti4AlN3
Nb4AlC3
V4AlC3
Ta4AlC3
Ti2GaC Ti2GaN
Ti
V 2GaC Cr2GaN
V
Cr2GaC V2GaN
Ga
Nb2Ga
Nb
Ti4GaC3
Mo C
Mo2Ga
Ta
C
Sc
Ta
Ti2GaC
Sc2InC
In Zr
Nb
Ti2InC
Hf
Zr2InC
Nb2InC
Hf2InC
Ti
Ti InN
Zr
Tl 2
Ti2TlC
Hf
Zr2TlC
Hf2TlC
Zr2TlN
211
312
M. Naguib, V. Mochalin, M.W. Barsoum, Y. Gogotsi, Adv. Materials, 26, 992 (2014)
M. Naguib, Y. Gogotsi, Acc. Chemical Research, 48, 128 (2015)
VA
VIA
Ti
Ti2SC
Zr
Ti
V
Si 3SiC2 P V2PC S Zr2SC
Nb 2SC
Nb 2PC
Ti4SiC3
Nb
Nb
Hf 2SC
Hf
Ge
Ti2GeC
V 2GeC
V
Cr 2GeC
Cr
Ti3GeC2
As
V2AsC
Nb
Nb2As
C
Ti4GeC3
Ti
Zr
Ti2SnC
Sn Nb
Zr2SnC
Hf
Nb2SnC
Hf2SnC
Hf
Ti 2SnN
Zr SnC2
Ti
Pb 3
Hf
Ti2PbC
Zr2PbC
Hf2PbC
413
B. Anasori
Structure of MXenes
4
21: Ti2C, V2C, Nb2C, (Ti0.5,Nb0.5 )2C Few atom thick
layered materials
ü  Transition metal oxide surface
32: Ti3C2, Ti3CN, ü  Conductive carbide core
(V0.5,Cr0.5)C2 43: Nb4C3, Ta4C3 M. Naguib, V. Mochalin, M.W. Barsoum, Y. Gogotsi, Adv. Materials, 26, 992 (2014)
M. Naguib, Y. Gogotsi, Acc. Chemical Research, 48, 128 (2015)
MXenes: A Family of Layered Solids
Ti3C2 MAX (Ti3AlC2) Ti2C 4 µm
Ta4C3 MXenes
1 µm
2 µm
3 µm
Thermally expanded graphite M. Naguib, et al. Adv. Mater. 23, 4248
(2011)
M. Naguib, et al. ACS Nano 6, 1322 (2012)
M. Naguib, et al. El. Comm. 16, 61 (2012)
O. Mashtalir, et al. Nature Comm. 4, 1716
(2013)
Ti3(C0.5N0.5 )2 1 µm
M. Naguib, et al. J. Am. Chem.
Soc. 135, 15966 (2013)
M. Naguib, et al., Adv. Mater. 26,
992-1005 (2014)
M.R. Lukatskaya, et al. Science 341,
1502 (2013)
Sh. Jin, et al.,
J. Phys: Conf. Ser. 188, 012040 (2009)
Single- and Multi-Layer MXene
Ti3C2
Optically transparent
~1 nm flake thickness
Ti3C2 TEM and SAED characterization
M. Naguib, et al. Advanced Materials 23, 4248 (2011),
J. Halim et al., Chem. Mater. 26, 2374 (2014), M. Naguib, et al.,
ACS Nano 6, 1322 (2012), M. Ghidiu et al., Nature 516, 78 (2014)
6
MXene Nanotubes and Nanoscrolls
MXene nanoscrolls have been
produced by sonication of MXene
colloidal solutions
MXene nanotubes have been
predicted and studied
computationally but have not been
produced experimentally yet
M. Naguib, et al., Adv. Mater. 23, 4248 (2011);
A. N. Enyashin, et al. Comp. Theor. Chem. 989, 27 (2012)
PDF Analysis of Ti3C2Tx Structure
(a) as-produced Ti3C2Tx, (b) Na+, (c) K+ intercalated Ti3C2Tx
C. Shi, et al. Phys. Rev. Letters, 112, 125501 (2014)
8
PDF Analysis of Nb4C3Tx Structure
M. Ghidiu, et al. Chem. Comm. 50, 9517 (2014)
Electronic Properties of MXenes
Y. Xie, et al. Phys. Rev. B 87, 235441 (2013); M. Khazaei, et al. Adv. Funct. Mater.
23, 2185 (2013); I. R. Shein, et al. Comp. Mater. Sci. 65, 104 (2012)
Effect of Surface Chemistry
11
M-atom
X-atom
X-atom
M-atom
•  All bare MXenes
monolayers are metallic
OH, F or O
surface group
•  OH, F and O terminated
MXenes are semiconducting
(band gap up to 2.0 eV)
Some MXenes exhibit magnetic behavior:
• 
• 
Bare Tin+1Xn (unlike functionalized), Tan+1Cn
OH- and F-functionalized Cr2C and Cr2N (unlike other terminated MXenes).
The Seebeck coefficients of semiconducting MXenes are predicted to be
comparable to the reported giant Seebeck coefficient for SrTiO3
(850 µV/K around 90 K)
M. Khazaei, et al., Adv. Funct. Mater. 23, 2185 (2013)
Q. Tang, et al., J. Am. Chem. Soc. 134, 16909 (2012)
Y. Xie, P. R. C. Kent, Physical Review B, 87, 235441 (2013)
Resistivity and Magnetoresistance
20 nm films
•  The weak localization model fits
the data to 2K, while the variable
range hopping does not.
•  Weak localization is a common
effect in metal films with
nanoscale thickness
J. Halim, et al. Chem. Mater. 26, 2374 (2014)
12
60 nm film
MXene Synthesis
Delaminated MXene
Delamination
Multilayered Mxene
Ti3C2Tx
HF Treatment
MAX phase
Ti3AlC2
13
DMSO intercalation
water swelling
SSA ≈ 23 m2/g
O. Mashtalir, et al. Nature Communications, 2013, 4, 1716
SSA ≈ 98 m2/g
Free-standing films made of Ti3C2Tx
14
… using aqueous solvent
… using organic solvent
Sonication in
water
Sonication in
propylene carbonate
1-3 mg/ml
1 µm
1 µm
•  Free-standing films ~1-5 micron thickness
•  Strong enough for handling
•  Highly conductive (up to 4000 S/cm)
•  Hydrophilic (but can be switched to hydrophobic)
M.R. Lukatskaya, et al., Science 341, 1502 (2013)
O. Mashtalir, unpublished
Tyndall effect
PVA-Ti3C2Tx Composites
15
10 wt.% PVA gel added:
•  Intercalation between the layers
•  Electrically conductive
!
Cross-sectional
TEM image
Z. Ling, et al., PNAS 111, 16676 (2104)
60 wt.% PVA gel added:
•  Uniform dispersion of single-layer
flakes in the polymer
•  Insulator
!
Composite MXene ﬁlms
(A) Ti3C2Tx, (B) Ti3C2Tx/PVA and, (C) Ti3C2Tx/PDDA films, and
(D) rolled shiny Ti3C2Tx film on a glass rod (diameter of 10 mm).
Z. Ling, et al., PNAS 111, 16676 (2104)
MXene ‘clay’: LiF+HCl method
Material behaves like a clay: can be easily rolled and shaped
And at the same time is highly conductive
M. Ghidiu, et al Nature, 2014, 516, 78-81
MXene ‘clay’| Easy electrode fabrication
Step 1: add water
Film is ready
in >15 min
Steps 2-3: roll and detach
M. Ghidiu et al., Nature 516, 78 (2014)
18
Properties of MXene “clay”
u  Rolling into films of controllable
thickness
u  Binder-free electrodes
u  Painting / Ink processing
u  Shaping into conductive solids
u  Reversible water swelling
M. Ghidiu et al., Nature 516, 78 (2014)
19
Intercalation from aqueous electrolytes
ü  Layered open structure that can
accommodate a range of differently
sized ions:
1 µm
Na+, K+, Mg2+, Al3+
ü  Many cations spontaneously intercalate into the MXene structure
ü  Polar molecules (amines, DMSO, hydrazine) intercalate too
M. Lukatskaya, et al. Science, 341, 1502 (2013)
Mechanisms of Charge Storage
Supercapacitors (ultracapacitors, double-‐layer capacitors, electrochemical capacitors) diﬀer in their electrical and electrochemical characterisJcs from baKeries. P. Simon, Y. Gogotsi, B. Dunn, Science, 343, 1210 (2014)
Electrochemical performance of Ti3C2Tx paper
Scan rate: 20 mV/s, 1 M KOH
J High volumetric capacitance, much higher than for porous
carbons (60-200 F/cm3 for activated graphene)
J Excellent cycling ability!
M. R. Lukatskaya, et al. Science, 2013, 341, 1502
22
Electrochemical performance of MXene ‘clay’
23
Clay (5 µm rolled film)
2X
Capacitance, F/cm3
1000
5 µm
800
600
30 µm
75 µm
400
200
0
1
2
5
10
20
50 100
Scan rate, mV/s
M. Ghidiu, et al. Nature, 2014, 516, 78
MXenes: 2D Transition Metals Carbides and Nitrides
>15 synthesized in about 4 years
Dozens predicted
M2AX
M3AX2
M4AX3
Etching “A” layer from Mn+1AXn + Sonication ð MXene
M2 X
M3X2
M4X3
M. Naguib, et al. Adv. Mater., 26, 992 (2014)
ü Metallic conductors
ü Narrow band-gap
semiconductors
ü Transparent in thin films
ü Hydrophilic
ü Can open band gap
ü Paper, films, composites
ü Polar molecules
intercalated
ü Cations intercalated: H+,
NH4+, Li+, Na+, K+, Cs+,
TMA+, Mg2+, Al3+ and other
Promising Applications of MXenes
  Aqueous (asymmetric) electrochemical capacitors
(M. Lukatskaya, Science 2013; Nature, 2014)
  Li-ion and Na-ion capacitors (J. Come, JES, 2013; X. Wang, Nature Comm., 2015)
  Li+, Na+, Mg2+ batteries (Y. Xie, JACS 2014, ACS Nano, 2014, )
  Catalysis (X. Li, IJHE, 2014; X. Xie, Nanoscale 2014; Chem. Comm. 2014)
  Multifunctional composites (Z. Ling, PNAS, 2014)
  Flexible & wearable energy storage devices
  Structural components
  Radiofrequency shielding
  Transparent conducting coatings (J. Halim, Mater. Chem, 2014)
  Sensors (J. Chen, Chem. Comm, 2014)
  Sorbents (O. Mashtalir, JMC A, 2014)
  Water purification (sorption of Pb and Cr ions)
(Q. Peng, JACS, 2014; Y. Ying, ACS Appl. Mater. Interf., 2015)
  Lubricant (X. Zhang, RSC Advances, 2015)
  Hydrogen storage (only modeling so far, Q. Hu, JPC A, 2013)
Thermoelectrics (only modeling so far, A. Khazaei, AFM, 2013)
  Electronic devices, heterostructures (only modeling so far, L.-Y. Gan, PRB, 2013, and
other)
European Collaborators and Funding
26
u Prof. Patrice Simon, Paul Sabatier University, France – capacitive energy
storage
u Prof. Thierry Djenizian, Aix-Marseille University, France – electrochemical
etching
u Dr. Encarnación Raymundo-Pinero, CNRS – CEMHTI, Orleans, France
thermal analysis + mass-spec
u Prof. Lars Hultman, Dr. Jun Lu, Dr. Per Eklund, Linkoping University,
Sweden – magnetron sputtering of MAX phase films, TEM (M. Barsoum)
u Dr. Volker Presser, University of Saarland, Germany - synthesis
u Prof. Clare Grey, Cambridge, UK, Nuclear Magnetic Resonance (NMR)
u Dr. Susan Sandeman, Univ. Brighton, UK – biocompatibility and cytotoxicity
Acknowledgments Current and former
students and
postdocs:
Dr. Michael Naguib
Dr. Vadym Mochalin,
Dr. Meng-Qiang Zhao
Dr. Babak Anasori
Dr. Majid Beidaghi
Maria Lukatskaya
Olha Mashtalir
Chang E. Ren
Zheng Ling
Yohan Dall’Agnese
Joseph Halim (M.B.)
Michael Ghidiu (M.B.)
Prof. Michel W. Barsoum, MSE Department, Drexel University
Prof. Steven May, Cole Smith, MSE Department, Drexel University
Prof. Simon Billinge, C. Shi, Columbia Univ.
Prof. M. Levi and Prof. D. Aurbach, Israel
Dr. Paul Kent and Dr. Yu Xie, ORNL
EERE
BATT