Ag - IPN Orsay

Metal Nanoparticles Stabilized
by Organic Ligands
Priyanka Ray, Cyril Martini, Vincent Huc,
Isabelle Lampre, Hynd Remita
Radiolytic synthesis of metal clusters
g, e e -, H O+, H•, OH•, H , H O
H2O
s
3
2
2 2
-
Selective reducing environment
•
•
(CH3)2CH OH + H•  (CH3)2C•OH + H2
(CH3)2CH OH + OH•  (CH3)2C•OH +
H2O
Isolated atoms as
precursors
Homogeneous nucleation
J. Belloni, Rad. Res., 150, S9, (1998)
J. Belloni et al., New J. Chem., 1239 (1998)
Process of reduction and nucleation
studied by pulse radiolysis
pulse
e-aq + Ag+
Ag0
k = 4.8 x 1010 dm3 mol-1 s-1
Ag0 + Ag+
Ag2+
k = 8.5 x 109 dm3 mol-1 s-1
Ag2+ + Ag+
Ag32+
k = 2 x 109 dm3 mol-1 s-1
Ag32+ + Ag32+
Ag42+ + 2 Ag+
Nucleation kinetics of silver clusters
Fast kinetics center Elyse
E. Janata et al., J. Phys. Chem., 98, 10888, (1994)
E. Janata, J. Phys. Chem., 107, 7334, (2003)
Advantages of radiolytic synthesis
Isolated atoms as precursors
Homogeneous nucleation
No addition of chemical reducing agents
High reducing power of solvated electons (reduction of
metals which are difficult to reduce by chemical methods
such as Fe, Co, Ni)
• Synthesis at room temperature
• In-situ synthesis in supports
• Bimetallic nanoparticles : control of the structure
(core/shell or alloy) and the composition by controlling the
dose rate
•
•
•
•
Metal nanoparticles synthesized by radiolysis
Silver nanoparticles stabilized by PVA
(polyvinyl alcohol)
Radiolysis
Gold nanoparticles stabilized by
PVA deposited on mica
 monodispersed particles
 size control
Stabilization of metal clusters by ligands or polymers
Ligands (CO, EDTA…)
-
-
-
-
m+
Agn
-
Polymers (polyacrylate)
-
m+
-
Ag
-
-
stabilisation par – COO -
-
n
-
-
STM Image of blue Ag
clusters
Ag73+ or Ag8 4+
(stable in air)
Steric effect
M. Mostafavi et al., Rad. Phys. Chem., 41, 453, (1993)
S. Remita et al., Chem. Phys. Lett., 218, 115, (1994)
Platinum clusters [Pt3(CO)6]n2- induced by radiolysis
Increasing dose
CO
2.03
O
Pt
Å
C
O
C
Pt
Å
OC 1. 80
2.66 Å
Pt
CO
C
1.17 Å
O
d = 2.66 Å
dinter-triangulaire = 3,10 Å
[Pt3(CO)6]n2-, (n=2-10)
[K2PtCl4] = 2,5 x
PtII
PtIV
ou
(n=2-10)
g, CO
[Pt3(CO)6]n2-,
10-4
•
M ; 1 atm. CO, water50 % / isopropanol 50 %
Colloides
(ligands, polymères)
Membranes
de polymères
Micelles
Zéolithes
Oxydes, Carbone,
Semiconducteurs
Nanotubes
de carbone
Electrodes
métalliques
Mésophases,
Matériaux
mésoporeux
Synthesis of metal nanoparticles on oxide supports
20 nm
Ag-modified TiO2
Application in photocatalysis
for water treatment
Au-Pt NPs on SiO2
Application in environmental
catalysis
Calix[8]arene
In collaboration with Vincent Huc and Cyril Martini (ICMMO)
Monomer unit
Calix[n]arene , where n= 4-16
The hydroxyl groups insure a dispersion in polar and
protic solvent such as ethanol and may be used for
post-derivatisation of these nanoobjects
Functional group known to
have an affinity for metal NPs
Calixarene stabilized Ag NPs
Ag NPs stabilized by Calixarene
Size distribution of AgNPs with Calixarene
HR TEM of Ag NPs stabilized calixarene
Scheme illustrating Ag NP stabilized
by calix[8]arene
Priyanka Ray, PhD thesis 2012
To be submitted
Ag-Calixarene Linkage
S-H
IR Spectra of Ag –Calixarene and Calixarene
showing the bond breakage between S-H
Fluoresent properties of Calix[8]arene-Ag NPs
UV-visible absorption and fluorescence (inset) spectra of
ethanolic solutions containing (a) 5  10-5 M calix[8]arene, (b) 5  10-4 M AgClO4,
(c) 5  10-5 M calix[8]arene and 5  10-4 M AgClO4 after overnight stirring prior to irradiation
and (d) 5  10-5 M calix[8]arene and 5  10-4 M AgClO4 after overnight stirring and irradiation to total reduction
Structural or Functional Effect?
The monomer form of Calixarene
Calix[8]arene
Cooperative effect due to the
macrocyclic structure of
calixarene
UV-Visible spectra of Ag and monomer of Calixarene (a)
before and (b) after 30 minutes radiation
Au NPs stabilized by calixarene
g-irradiation
Polydisperse AuNPs
Functionalized Calixarenes
g-irradiation
Functionalized Calixarene with Au directly attached
to its arms
Monodisperse Au-NPs of 1.4 nm
Synthesis of 1D, 2D and 3D nanomaterials
Au Nanorods
Pt nanowires
Pd urchins
50 nm
20 nm
Pd nanowires
Applications in:
Pd nanosheets
Pt porous nanoballs
Polymer nanowires
- Catalysis
- Electrocatalysis and fuel cells
- Hydrogen storage
Abidi, W. et al. J. Phys. Chem. C 114 , 14794, 2010.
Ksar F. et al. Chem. Mater. 21, 1612, 2009,
Ksar F. et al. Chem. Mater. 21, 3677, 2009.
PF. Siril et al. Chem. Mater. 21, 5170, 2009.
Ksar F. et al. Nanotechnology, 22 , 305609, 2011.
Radiolytic Synthesis
of ultra small ZnS nanoparticles
g
H 2O 
eaq , H 3O  , H  , OH  , H 2 , H 2O2
2

aq
Zn  e  Zn
a
b
2 nm

In the presence of thiols :
Zn2  HS   ZnS  H 
20 nm
The size of formed ZnS nanoparticles is very small
compared to those prepared by chemical methods.
A.H. Souici et al. Chem. Phys. Lett. 2006, 422, 25.
Optical properties of ultra small ZnS nanoparticles
Energy (eV)
2.5
5.16
4.76
4.43
4.13
3.87
10
1.2
Absorbance
8
0.4
5'
4'
1.5
4
0.0
4
8
12
16
20
Dose (kGy)
1.0
6
7
8
9
10
1
0.0
230 240 250 260 270 280 290 300 310 320
5
0
0.5
5
265 nm
285 nm
240 nm
0.8
Intensity (x10 )
Absorbance
2.0
6
3'
3
4
2'
2
2
1'
1
Wavelength (nm)
0
240
Absorption spectra of ZnS clusters: Curves 6 to 10
correspond respectively to 3.6, 5.6, 7.2, 12 and 16.8
kGy. Dose rate is 3.6 kGy h-1.
280
320
360
400
Wavelength (nm)
440
Photoluminescence spectra (PL) (1-5)
(excitation wavelength at 250 nm) and
photoluminescence excitation spectra (PLE)
(1’–5’) with emission at 400 nm.
The mechanism of fluorescence arises from radiative recombination of deeptrapped carriers and surface states.
A.H. Souici et al. Chem. Phys. Lett. 2006, 422, 25.
Synthesis of CuS nanostructures
Radiolysis of CuCl2 in the presence of sodium thiosulfate Na2S2O3
CuS hollow spheres
CuS nanotubes
Zibin Hai, PhD thesis 2012
to be submitted
Iron oxyhydroxide formation
by gamma-radiolysis
P. A. Yakabuskie et al. Phys. Chem. Chem. Phys. 2011,13, 7198.
Conclusion
 Radiolysis is a powerful method to synthesize metal
nanoparticles and nanostructured materials of
controlled size, shape and structure
 In situ synthesis in supports
 Quantum dots and oxide nanoparticles of controlled
size can also be synthesized by radiolysis
Acknowledgements
Isabelle Lampre (LCP, Orsay)
Priyanka Ray (LCP, Orsay)
Cyril Martini (ICMMO, Orsay)
Vincent Huc (ICMMO, Orsay)
Anaïs Lehoux (LCP, Orsay)
Zibin Hai (LCP, Orsay)
Nadia El Koli (LCP, Orsay)
Mehran Mostafavi (LCP, Orsay)
Jacqueline Belloni (LCP, Orsay)
Samy Remita (LCP, Orsay)
Laurence Ramos (LVCN, Montpellier)
Patricia Beaunier (LRS, Paris VI)
Laurence Ramos (L2C, Montpellier)
Arnaud Etcheberry (ILV, Versailles)
Radiolytic Synthesis
of ultra small ZnS nanoparticles
g
H 2O 
eaq , H 3O  , H  , OH  , H 2 , H 2O2
Irradiation of
Zn2+
a
b
2 nm
in the presence of thiols
Zn2  eaq  Zn
Zn2  HS   ZnS  H 
20 nm
The size of formed ZnS nanoparticles is very small
compared to those prepared by chemical methods.
A.H. Suici et al. Chem. Phys. Lett. 2006, 422, 25.
Calix[8]arene with Ph functionality
g radiation
2 nm
Ph functionalised Calixarene with Au directly attached,
subjected to gamma irradiation
produced particles of 2 nm diameter.