Permanent Staff
• Catherine Amiens, Professeur
• Diana Ciuculescu-Pradines, Maître de Conférences
• Léa Godard, Technicienne (50%)
The major focus of our research projects is the synthesis of novel nano-objects and their applications, both chemical and physical. The synthesis of metal or metal oxide nanoparticles is performed through an organometallic approach. A strong effort is devoted to surface characterization and chemistry. Applications in biology, catalysis, microelectronics, optics or magnetism are developed. Most of projects are managed in a context of multi-disciplinarity within international and/or industrial collaborations.
Keywords: – Organometallic Synthesis – Nanochemistry – Metals – Metal Oxides – Nanoparticles – Nanomaterials – Nanostructures – Surface Functionalization and Reactivity – Biology – Catalysis – Energy – Magnetism – Microelectronics – Photophysics –
Engineering of Metal
Nanoparticles
Karine Philippot Directrice de Recherche Tel: +33 5 61 33 32 30 Fax: +33 5 61 55 30 03
karine.philippot@lcc-toulouse.fr
An organometallic methodology for the synthesis of nanoparticles and nanomaterials
A versatile approach is developed for the synthesis of metal and metal oxide nanoparticles of controlled size (1-100 nm), size dispersity, surface state, shape and organization. The method consists in the decomposition of a metallic precursor under a gas atmosphere (CO,H2,H2O) in mild conditions. The stabilization is achieved by polymer or ligand shells. Shape controlled nano-objects and ordered nanocrystal super- lattices accommodating identical particles may be obtained either by a judicious combination of ligands/surfactants and/or by supports treatments. A particular attention is devoted to the characterization of the nanostructures to study the relationships between structure and properties. Current studies concern the chemical and physical properties of the particles (structural, magnetic, optical or electrical), with applications in biology, catalysis, microelectronics and optoelectronics…
Examples of nano-objects: Au (a) and Ru (b) nanoparticles, Pt nanocubes deposited onto alumina (c) and Co nanowires (d).
Surface functionalization and water transfer
Common ligands already known to stabilize organometallic complexes like 1,3,5-triaza-7-phosphaadamantane (PTA), sulfonated diphosphines and cyclodextrines were used to prepare water-soluble metal NPs. The synthesis of the nanoparticles is performed by simple decomposition of the precursor in usual conditions and in the presence of an amphiphilic ligand. The so-obtained nanoparticles are easily redispersed in water leading to stable aqueous solutions..
PTA-stabilized Pt nanoparticles synthesized in THF (left) and after dispersion in water (right), with a mean size of 0,9
(0,1) and 1,1 (0,2) nm, respectively
Nanoparticles for microelectronics
Strain gauges are studied with the LPCNO Nanotech team.
Gold nanoparticles are deposited onto flexible substrates via a convective self-assembly process affording lines of nanoparticles of controllable width and thickness. The conductivity of these lines varies as a function of the strain applied to the substrate with a sensitivity suitable to make touch-sensitive surfaces. This technology is presently developed by Nanomade,
From left to right: AuNPs assembly, scheme of a strain gauge, image of the device showing its flexibility
Nanoparticles for nanomedecine
Based on our know-how in the synthesis of bimetallic nanoparticles, we develop Bi@Fe nanohybrids (a bismuth core surrounded by an iron shell) and study their oxidation and stability in water to afford dual contrast agents for CT (high X-Ray absorption of bismuth core) and MRI imaging (property of the iron oxide shell). Location of iron at the surface should lead to optimum activity in MRI and biocompatibility. This project is carried out in collaboration with biologists and radiologists.
Chemical distribution in FeBi nano-objects red: iron, green: bismuth
Selected Recent Publications
• Organometallic approach for the synthesis of nanostructures, C. Amiens, B. Chaudret,D. Ciuculescu- Pradines, V. Collière, K. Fajerwerg, P. Fau, M. Kahn, A.
Maisonnat, K. Soulantica, K.Philippot, New J. Chem., 2013, 37 (11), 3374 – 3401,
• Unexpected chemical distribution in iron bismuth bimetallic nanospheres, J. G. Mattei, F. Pelletier, D.
Ciuculescu, P. Lecante, J.C. Dupin, N. Yaacoub, J. Allouche, J. M. Greneche, D. Gonbeau, C. Amiens, and M.J.
Casanove, J. Phys. Chem. C, 2013, 117, 1477-1484.
• Taking advantage of a terpyridine ligand for the deposition of Pd nanoparticles onto a magnetic material for selective hydrogenation reactions, M. Guerrero, N. J.
S. Costa, L. L.R. Vono, L. M. Rossi, E. V. Gusevskaya,K.
Philippot, J. Mater. Chem. A, 2013, 1 (4), 1441-1449.
• Efficient Ruthenium Nanocatalysts in Liquid-Liquid Biphasic Hydrogenation Catalysis: towards a Supramolecular Control via a Sulfonated Diphosphine / Cyclodextrin Smart Combination, M. Guerrero, Y. Coppel, N. T. T. Chau, A. Roucoux, A. Denicourt-Nowicki, E.
Monflier, H. Bricout, P. Lecante, K. Philippot, Chem.Cat.Chem., 2013, 12, 3802-3811.
Magnetic nano-objects
We aim at evidencing size, shape and surface effects on magnetization and anisotropy of monometallic (Co, Ni, Fe…) or bimetallic systems (CoPt, CoRu, CoRh…) as well as oxides. Recently we evidenced the photomodulation of the magnetization of Co nanoparticles under irradiation of RhB dyes grafted at their surface. This could allow applications in the magnetic data storage technology.
Scheme of photoinduced electron transfer between RhB and Co NPs and consequences on magnetisation
Nanoparticles for catalysis
Noble metal nanoparticles stabilized in solution with a ligand or deposited on a support (silica, carbon derivatives, ionic liquids…) are developed for applications in catalysis. Efforts are devoted to tune the nanocatalysts properties by an adequate choice of the ligand or support depending on the target catalysis as well as to their recovery. For example, very small RuNPs (ca,1,6 nm) were prepared using a sulfonated diphosphine with a Rame-β-cyclodextrin. This combination not only increased the stability of the aqueous colloidal solution but also improved the catalytic performance of the RuNPs in terms of reactivity and selectivity. The deposition of Ru and Pd NPs onto porous carbons allowed to catalyze selectively the oxidation of benzyl alcohol into benzaldehyde with an easy recycling of the catalyst.
Selective oxidation of benzyl alcohol in water with Ru or PdNPs@Carbon nanomaterials and recycling study Selective hydrogenation of styrene and acetophenone in water with
Ru nanoparticles and recycling study
