排序方式: 共有13条查询结果,搜索用时 218 毫秒
1.
Concepción P Corma A Silvestre-Albero J Franco V Chane-Ching JY 《Journal of the American Chemical Society》2004,126(17):5523-5532
Pt on mesostructured CeO(2) nanoparticles embedded within ultrathin layers of highly structured SiO(2) binder shows highest activity reported with 80% selectivity for the chemoselective hydrogenation of crotonaldehyde. Characterization by transmission electron microscopy (TEM), CO adsorption, and X-ray photoelectron spectroscopy (XPS) show the presence of small Pt metal particles, preferentially located on CeO(2) (70%) together with the formation of Pt-CeO(2-x) sites at the interface between Pt and CeO(2) (4 nm) nanoparticles. These sites are able to polarize the carbonyl group and facilitate the selective hydrogenation of this with respect to the double bond. 相似文献
2.
Chane-Ching JY Airiau M Sahibed-dine A Daturi M Brendlé E Ozil F Thorel A Corma A 《Langmuir : the ACS journal of surfaces and colloids》2005,21(4):1568-1574
We demonstrated the surface composite character down to the nanometer scale of SiO(2)-CeO(2) composite high surface area materials, prepared using 5 nm colloidal CeO(2) nanoparticle building blocks. These materials are made of a homogeneous distribution of CeO(2) nanoparticles in thin layers of SiO(2), arranged in a hexagonal symmetry as shown by small-angle X-ray scattering and transmission electron microscopy. Since the preparation route of these composite materials was selected in order to produce SiO(2) wall thickness in the range of the CeO(2) nanoparticle diameter, these materials display surface nanorugosity as shown by inverse chromatography. Accessibility through the porous volume to the functional CeO(2) nanoparticle surfaces was evidenced through an organic acid chemisorption technique allowing quantitative determination of CeO(2) surface ratio. This surface composite nanostructure down to the nanometer scale does not affect the fundamental properties of the functional CeO(2) nanodomains, such as their oxygen storage capacity, but modifies the acid-base properties of the CeO(2) surface nanodomains as evidenced by Fourier transform IR technique. These arrays of accessible CeO(2) nanoparticles displaying high surface area and high thermal stability, along with the possibility of tuning their acid base properties, will exhibit potentialities for catalysis, sensors, etc. 相似文献
3.
Mahé N Guillou O Daiguebonne C Gérault Y Caneschi A Sangregorio C Chane-Ching JY Car PE Roisnel T 《Inorganic chemistry》2005,44(22):7743-7750
The synthesis of hexanuclear lanthanide hydroxo complexes by controlled hydrolysis led to polymorphic compounds. The hexanuclear entities crystallize in four different ways that depend on the extent of their hydration. The four structures can be described as hexanuclear lanthanide entities with formula [Ln(6)(mu(6)-O)(mu(3)-OH)(8)(NO(3))(6)(H(2)O)(12)](2+). Two additional NO(3)(-) ions intercalate between the hexanuclear entities in order to ensure the electroneutrality of the crystal structure. Some crystallization water molecules fill the intermolecular space. The three first families of compounds (1-3) exhibit crystal structures that have previously been reported. The fourth family of compounds (4) is described here for the first time. Its chemical formula is [Ln(6)(mu(6)-O)(mu(3)-OH)(8)(NO(3))(6)(H(2)O)(12)](NO(3))(2).2H(2)O (Ln = Gd, Er, and Y). In this paper, the chemical and thermal stabilities of the hexanuclear lanthanide compounds are reported together with the magnetic properties of the Gd(III)-containing species. To use these entities as precursors for new materials, the substitution of the nitrato groups by chloride ions has been studied. Two byproduct compounds have so been obtained: The first (compound 5) is a nitrato/chloride hexanuclear compound of chemical formula [Er(6)(mu(6)-O)(mu(3)-OH)(8)(NO(3))(6)(H(2)O)(12)](NO(3))Cl.2H(2)O. The second one (compound 6) is a polymeric compound in which the hexanuclear entities are linked by an unexpected and original N(2)O(4) bridge. Its chemical formula is [Er(6)(mu(6)-O)(mu(3)-OH)(8)(NO(3))(4)(H(2)O)(11)(OH)(ONONO(2))]Cl(3).2H(2)O. Its crystal structure can be described as the juxtaposition of chainlike molecular motifs. To the best of our knowledge, this is the first example of a coordination polymer synthesized from an isolated polylanthanide hydroxo complex. 相似文献
4.
Mathieu Lazerges Kathleen Isabelle Chane-Ching Salah Aeiyach Saloua Chelli Brigitte Pepin-Donat Martial Billon Christian Lombard François Maurel Mohamed Jouini 《Journal of Solid State Electrochemistry》2009,13(2):231-238
The electrochemical oxidation of hexa-N-pyrrolylbenzene in organic media leads, via intramolecular coupling of the pyrrole residues, to the deposition of a molecular
semiconductor film on an electrode surface. In situ electron spin resonance–electrochemical experiments reveal that the semiconductor
is endowed with both properties of conducting polymers (i.e., reversible oxidation) and polyaromatic molecular materials (i.e., highly paramagnetic). The material, which is easy to process as soft homogeneous thin film, shows a tunable 0 to 1 spin
concentration per molecule at room temperature by controlling the electrochemical potential.
Contribution to the Fall Meeting of the European Materials Research Society, Symposium D: 9th International Symposium on the
Electrochemical–Chemical Reactivity of Metastable Materials, Warsaw, 17th–21st September, 2007.
An erratum to this article can be found at 相似文献
5.
Conducting polymer electrochemical switching as an easy means for designing active plasmonic devices
Leroux YR Lacroix JC Chane-Ching KI Fave C Félidj N Lévi G Aubard J Krenn JR Hohenau A 《Journal of the American Chemical Society》2005,127(46):16022-16023
Due to the continuously increasing demand for ultimate miniaturization of electronic and photonic systems, molecular electronics and plasmonic devices are currently booming as alternative technologies because of their very promising potential in writing, reading, storing, and processing information at the nanoscale. Conducting polymers or oligomers have been proposed and used as basic building blocks in molecular and plastic electronics since the end of the 80s. Plasmonics is, on the other hand, an emerging branch of photonics which uses nanostructured materials that support surface plasmons. Among plasmonic devices, active plasmonic devices are still lacking. In this work, we report on new active molecular plasmonic devices in which the electrochemical switching of a nanometric film of conductive polymer between its reduced and oxidized state is used in order to control, switch, and modulate localized surface plasmon (LSP) resonance of gold nanoparticle arrays. 相似文献
6.
Integrating Al with NiO nano honeycomb to realize an energetic material on silicon substrate 总被引:3,自引:0,他引:3
Kaili Zhang Carole Rossi Pierre Alphonse Christophe Tenailleau Simon Cayez Jean-Yves Chane-Ching 《Applied Physics A: Materials Science & Processing》2009,94(4):957-962
Nano energetic materials offer improved performance in energy release, ignition, and mechanical properties compared to their
bulk or micro counterparts. In this study, the authors propose an approach to synthesize an Al/NiO based nano energetic material
which is fully compatible with a microsystem. A two-dimensional NiO nano honeycomb is first realized by thermal oxidation
of a Ni thin film deposited onto a silicon substrate by thermal evaporation. Then the NiO nano honeycomb is integrated with
an Al that is deposited by thermal evaporation to realize an Al/NiO based nano energetic material. This approach has several
advantages over previous investigations, such as lower ignition temperature, enhanced interfacial contact area, reduced impurities
and Al oxidation, tailored dimensions, and easier integration into a microsystem to realize functional devices. The synthesized
Al/NiO based nano energetic material is characterized by scanning electron microscopy, X-ray diffraction, differential thermal
analysis, and differential scanning calorimetry. 相似文献
7.
Chane-Ching JY Gillorin A Zaberca O Balocchi A Marie X 《Chemical communications (Cambridge, England)》2011,47(18):5229-5231
Quaternary chalcopyrite (Cu(2)CoSnS(4), Cu(2)ZnSnS(4)) nanocrystals displaying high crystallization and controlled morphology were synthesized via a high-temperature growth regime achieved by dissolution-reprecipitation of tailored ultrafine precursors in the temperature range 400-500 °C. 相似文献
8.
Fabienne Alary Jean-Louis Heully Anthony Scemama Bénédicte Garreau-de Bonneval Kathleen I. Chane-Ching Michel Caffarel 《Theoretical chemistry accounts》2010,126(3-4):243-255
Density functional theory (DFT) and ab initio computations are applied to examine different properties of diamagnetic, square planar neutral nickel complexes that contain two bidentate ligands derived from bis ((ethylene)-1,2-dithiolato) ligands. Geometry, vibrational spectra (IR and Raman) are well reproduced in the density functional framework whereas TD-DFT methods are clearly insufficient to reproduce absorption properties. Multiconfigurational perturbation theory based on a complete active space self-consistent field wave function, i.e. MRPT2 and MRPT4 methods, reveal the pronounced multiconfigurational character of the ground state wave function. The singlet–triplet energy gap, the energy gained from symmetry breaking and the singlet diradical character are discussed in the DFT and ab initio frameworks. The complex of interest does not display a strong singlet diradical character. This molecule having a peculiar electronic structure; strong delocalization as shown by a new electron pair localization function analysis (EPLF); exemplifies the fragility of the TD-DFT method and thus, caution should be taken in the determination of the energetic properties of such compounds. 相似文献
9.
Kaili Zhang Christophe Tenailleau Pierre Alphonse Jean-Yves Chane-Ching 《Applied Physics A: Materials Science & Processing》2010,100(4):1049-1055
Aligned three-dimensional single-crystal chromium nanostructures are fabricated onto a silicon substrate by thermal evaporation
in a conventional thermal evaporator, where the incident angle of Cr vapor flux with respect to the substrate surface normal
is fixed at 88°. The effects of the deposition time and incident angle on the morphology of the resulting nanostructures are
investigated. The achieved Cr nanostructures are characterized by scanning electron microscopy, energy dispersive X-ray analysis,
X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, and surface area measurement.
This study provides a convenient way to fabricate three-dimensional single-crystal Cr nanostructures, which is suitable for
batch fabrication and mass production. Finally, the same technique is employed to fabricate the nanostructures of other metals
such as Ag, Au, Pd, and Ni. 相似文献
10.
Chane-Ching JY Cobo F Aubert D Harvey HG Airiau M Corma A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(3):979-987
A general synthetic method for the preparation of nanostructured materials with large surface area was developed by using nanoparticle building blocks. The preparation route involves the self-assembly of functionalized nanoparticles in a liquid-crystal phase. These nanoparticles are functionalized by using difunctional amino acid species to provide suitable interactions with the template. Optimum interactions for self-assembly of the nanoparticles in the liquid-crystal phase were achieved with one -NH2 group anchored to the nanoparticle surface per 25 A(2). To maximize the surface area of these materials, the wall thicknesses are adjusted so that they are composed of a monolayer of nanoparticles. To form such materials, numerous parameters have to be controlled such as the relative volume fraction of the nanoparticles and the template and size matching between the hydrophilic component of the copolymer and nanoparticles. The surface functionalization renders our synthetic route independent of the nanoparticles and allows us to prepare a variety of nanostructured composite materials that consist of a juxtaposition of different discrete oxide nanoparticles. Examples of such materials include CeO2, ZrO2, and CeO2-Al(OH)3 composites. 相似文献