Fu Doped
nd
ed
by
and co-doped Graphene on Copper metal substrate:
Properties and molecular oxygen reactivity
Lara Ferrighi, Cristiana Di Valentin
Università di Milano-Bicocca, MILANO, Italy
Abstract
Electronic properties
The electronic properties of G, Boron-doped G (BG), Nitrogendoped G (NG) and co-doped BNG on Cu(111) are
investigated with DFT by means of:
● Substitutional chemical doping
● Metal doping
● Lattice parameter strain
The O2 reactivity is investigated both on the metal supported
G and BG and at the interface with the metal.
Density of states of free-standing G (gray area), BG, NG and BNG.
Computational details
●
●
●
4x4 supercell, 3% doping, 6% co-doping
Quantum espresso package
C09x
vdw-DF2
functional
L. Ferrighi, M. Trioni and C. Di Valentin
J. Phys. Chem. C, 2015, 119, 6056
Density of states of Cu supported BG.
L. Ferrighi and C. Di Valentin
Surface Science, 2015, 634, 68
Adsorption
Oxygen dissociation
Table 1. Adsorption energies per C atom Eads (in eV), charge
transfer per C atom δq (in e), and equilibrium distances heq (in Å)
Additional adsorption energies ΔEads per dopant (in eV) and charge
transfer difference Δδq (in e) for doped and co-doped graphene on
Cu(111) with respect to pure G.
vdw-DF2
C09x
lattice
2.47 Å
2.52 Å
strain
0%
2%
Eads
q
heq
Eads
q
heq
-0.061
2x10-3
3.24
-0.065
6x10-3
3.13
Eads
q
heq
Eads
q
heq
BtG
-0.55
0.45
2.46(B)/3.02(C)
-0.79
0.56
2.52(B)/2.84(C)
BhG
-0.76
0.47
2.14(B)/2.98(C)
-0.97
0.49
2.23(B)/2.78(C)
NtG
-0.14
-0.17
3.35(N)/3.32(C)
-0.02
-0.22
3.25(N)/3.21(C)
N hG
-0.14
-0.17
3.36(N)/3.34(C)
-0.02
-0.22
3.24(N)/3.21(C)
BtNhG
-0.04
0.01
3.21(B)/3.21(N)
-0.06
0.04
3.02(B)/3.10(N)
BhNtG
-0.07
0.05
3.09(B)/3.19(N)
-0.09
0.01
3.01(B)/3.10(N)
G
On top of BG
+0.31
Lattice parameter strain effect
Expanding G lattice:
the adsorption is stronger
the corrugation is damped
+0.30
-0.43
On coated Cu
Free Cu
-2.76
-3.18
-2.12
-1.98
-1.51
At the interface
Pure G/Cu interaction
The G/Cu interaction is rather weak
Cu is donating electrons to G (n-type doping)
Doping effect
BG adsorption is much stronger
BG/Cu distance is shorter
NG/Cu distance is longer
BNG/Cu is similar to G/Cu
+0.26
-0.71
+2.22
-1.36
-1.75
Conclusions
The presence of G or BG damps Ediss of O2 on Cu(111)
O2 prefers Cu rather than the Cu/G interface
O2 dissociation at the Cu/BG interface is competitive close
to the dopant
CHECK OUT OUR WEBSITE at www.beyond-graphene.mater.unimib.it