Spectroscopic and AFM studies of the functionalisation of carbon
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Surface science & catalysis group Cardiff Catalysis Institute 1 XPS, AFM & DFT studies of the functionalization of graphite Dr Philip R. Davies Carlo Buono a , Robert J. Davies b , Thomas Jones a , Jiří Kulhavý c , Ryan Lewis a , David J. Morgan a , Neil Robinson a and David J. Willock a Cardiff Catalysis Institute School of Chemistry, Cardiff University Cardiff
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Short presentation to the Faraday discussion No. 173 about our studies of functional groups at carbon surfaces. We have selectively derivatised oxygen groups and can unambiguously identify OH and C=O groups. We are also fairly confident about the presence of O-C-O!
Transcript of Spectroscopic and AFM studies of the functionalisation of carbon
Surface science & catalysis group
Cardiff Catalysis Institute
1
XPS, AFM & DFT studies of the functionalization of graphite
Dr Philip R. Davies Carlo Buonoa, Robert J. Daviesb, Thomas Jonesa, Jiří
Kulhavýc, Ryan Lewisa, David J. Morgana, Neil Robinsona and David J. Willocka
Cardiff Catalysis Institute
School of Chemistry, Cardiff University Cardiff
Surface science & catalysis group
Cardiff Catalysis Institute
2
Motivation • Carbon catalyst supports • Graphene based sensors • Intracellular nanodiamond sensors
HOPG
• Multilayer graphene • Ambient preparation conditions • Surface sensitive analysis • DFT analysis of surface chemistry
• Highly ordered pyrolytic graphite (HOPG) Strategy
Surface science & catalysis group
Cardiff Catalysis Institute
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Mild acid treatment of HOPG
What are the oxygen states? How do they affect Carbon-Metal interactions?
527 532 537 542 Binding energy /eV
O(1s) O(1s) O(1s)
(a) Clean
(b) HCl
(c) HCl/573K
531.5 O(1s)
533.3
HOPG
Surface science & catalysis group
Cardiff Catalysis Institute
4
Molecule specific labeling: Is OH(a) present?
679 684 689 694 699 Binding energy /eV
688.8
(d) HCl/573 K & TFAA
(c) HCl/TFAA
(a) Clean/TFAA
F(1s)
527.0 532.0 537.0 542.0 Binding energy /eV
532.6 534.0
531.6
(a) Clean
(b) HCl
(c) HCl/TFAA
O(1s)
(d) HCl/ 573 K & TFAA
OH(a) + CF3C(O)OC(O)CF3 (g) à CF3C(O)O-(a) + CF3CO2H(g)
OH(a) 532.6 eV
Not all OH is functionalised
Surface science & catalysis group
Cardiff Catalysis Institute
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Is –CO2H present?
679 684 689 694 699 Binding energy /eV
F(1s)
(a) Clean/TFE
(b) HCl/TFE
(c) HCl/573 K & TFE
688.4
Not significantly!
-CO2H(a) + CF3CH2OH(g) à CF3C(OH)O-(a) + H2O(g)
Surface science & catalysis group
Cardiff Catalysis Institute
6
C=O ?
680 685 690
688.4
F(1s)
(a)
(d)
(c)
Binding energy /eV
Clean HCl /TFH HCl /573 K /TFH
-CO(a) + CF3CH2NH-NH2 (g) à CF3CH2NH-N=(a) + H2O(g)
C=O(a) 531.5 eV
527 532 537 542 Binding energy /eV
O(1s) O(1s) O(1s)
(a) Clean
(b) HCl
(c) HCl/573K
531.5 O(1s)
533.3
OH(a) 532.6 eV
-C-O-C-(a) 533.3 eV
Surface science & catalysis group
Cardiff Catalysis Institute
7
Gold deposition
78 83 88 93 Binding energy /eV
Au(4f) 84.0!86.5!
(a) Clean!
(b) HCl /Au!
(c) HCl /573 K & Au!
84.9!
HOPG
OH(a)
C=O C-O-C
195 200 205 Binding energy /eV
Cl(2p)
(a)
(b)
(c)
198.0
199.7
Au0
Au3+
Surface science & catalysis group
Cardiff Catalysis Institute
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The Stability of Functional Groups: DFT • Calculated stable structure for
OH at graphite edges
• High OH density
• See Poster 38 for OH….Au
Surface science & catalysis group
Cardiff Catalysis Institute
9
Gold 2015 7th International Gold Conference 26th – 29th July 2015 in Cardiff, UK
www.cardiff.ac.uk/gold2015 Abstract submission 1st September – 14th October 2014
Surface science & catalysis group
Cardiff Catalysis Institute
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