Metal Nanoparticles Stabilized by Organic Ligands Priyanka Ray, Cyril Martini, Vincent Huc, Isabelle Lampre, Hynd Remita
Radiolytic synthesis of metal clusters H 2 O g, e - e s-, H 3 O +, H, OH, H 2, H 2 O 2 Selective reducing environment (CH 3 ) 2 CH OH + H (CH 3 ) 2 C OH + H 2 (CH 3 ) 2 CH OH + OH (CH 3 ) 2 C OH + H 2 O 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 + Ag 0 k = 4.8 x 10 10 dm 3 mol -1 s -1 Ag 0 + Ag + Ag 2 + k = 8.5 x 10 9 dm 3 mol -1 s -1 Ag 2+ + Ag + Ag 3 2+ k = 2 x 10 9 dm 3 mol -1 s -1 Ag 3 2+ + Ag 3 2+ Ag 4 2+ + 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) Gold nanoparticles stabilized by PVA deposited on mica Radiolysis monodispersed particles size control
Stabilization of metal clusters by ligands or polymers Ligands (CO, EDTA ) Polymers (polyacrylate) - - Ag n m+ - - - - - - - - Ag n m+ - - - STM Image of blue Ag clusters Ag 7 3+ or Ag 8 4+ (stable in air) stabilisation par COO - - Steric effect M. Mostafavi et al., Rad. Phys. Chem., 41, 453, (1993) S. Remita et al., Chem. Phys. Lett., 218, 115, (1994)
Platinum clusters [Pt 3 (CO) 6 ] n 2- induced by radiolysis CO Increasing dose O C Pt 2.03 Å C O OC 1.80 Å Pt 2.66 Å C Pt CO 1.17 Å O d = 2.66 Å d inter-triangulaire = 3,10 Å [Pt 3 (CO) 6 ] n 2-, (n=2-10) [K 2 PtCl 4 ] = 2,5 x 10-4 M ; 1 atm. CO, water50 % / isopropanol 50 % g, CO Pt II ou Pt IV [Pt 3 (CO) 6 ] 2- n, (n=2-10)
Colloides (ligands, polymères) Micelles Oxydes, Carbone, Semiconducteurs Electrodes métalliques Membranes de polymères Zéolithes Nanotubes de carbone Mésophases, Matériaux mésoporeux
Synthesis of metal nanoparticles on oxide supports 20 nm Ag-modified TiO 2 Au-Pt NPs on SiO 2 Application in photocatalysis for water treatment 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 HR TEM of Ag NPs stabilized calixarene Size distribution of AgNPs with 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 AgClO 4, (c) 5 10-5 M calix[8]arene and 5 10-4 M AgClO 4 after overnight stirring prior to irradiation and (d) 5 10-5 M calix[8]arene and 5 10-4 M AgClO 4 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 Functionalized Calixarenes Polydisperse AuNPs 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 Pd urchins Pt nanowires 50 nm 20 nm Pd nanowires Pd nanosheets Pt porous nanoballs Polymer nanowires Applications in: - 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 H 2 O g eaq H3O, H, OH, H 2,, H O 2 Zn e aq Zn 2 2 a b 2 nm In the presence of thiols : 2 Zn 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.
Intensity (x10 5 ) Absorbance Absorbance Optical properties of ultra small ZnS nanoparticles 2.5 2.0 1.5 1.0 0.5 Energy (ev) 5.16 4.76 4.43 4.13 3.87 1 6 1.2 0.8 0.4 265 nm 285 nm 240 nm 0.0 0 4 8 12 16 20 7 Dose (kgy) 0.0 230 240 250 260 270 280 290 300 310 320 8 9 Wavelength (nm) 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. 10 10 8 6 4 2 5' 4' 3' 2' 1' 0 240 280 320 360 400 440 Wavelength (nm) Photoluminescence spectra (PL) (1-5) (excitation wavelength at 250 nm) and photoluminescence excitation spectra (PLE) (1 5 ) with emission at 400 nm. 4 3 2 1 5 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 CuCl 2 in the presence of sodium thiosulfate Na 2 S 2 O 3 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 H 2 O g eaq H3O, H, OH, H 2,, H O Irradiation of Zn 2+ in the presence of thiols 2 2 a b 2 nm 2 Zn e aq Zn 2 Zn 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 n m Ph functionalised Calixarene with Au directly attached, subjected to gamma irradiation produced particles of 2 nm diameter.