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Influencing the morphology of three dimensional LDH nanostructures based on amino-acid complex precursors
|Vanessa Prevot , Nathalie Gaillard-Caperaa , Claude Forano|
BLAISE PASCAL UNIVERSITY, 24 Av des landais, Aubiere 63177, France
Layered Double Hydroxides (LDHs) are very attractive materials due to their high versatility and wide range of composition. They are developed for a large number of applications as anionic exchangers, adsorbants, catalysts and catalyst precursors or as filler for polymers. These materials are described by general formula [MII1-xMIIIx(OH)2] [Am-x/m.H2O] with MII = Mg2+, Zn2+, Ni2+, Co2+, Cu2+..., MIII = Al3+, Cr3+, Fe3+, Ga3+...) and A = inorganic or organic anions. The great variety of metal and interlayer species combinations allows to tailor their physical (magnetic, optical, electrochemical) and chemical properties (redox and acido-basic properties) for different specific applications. LDH are usually obtained prepared by the constant pH coprecipitation method. Moreover, in order to tune and improve the textural properties of these coumpounds (surface area, morphology, particle size), other synthesis methods have to be proposed.
In this work, we have synthesized three dimensional nanostructures of NiAl-based LDH (5-10mm) via a novel approach using a strong alkaline solution of amino acid. Under hydrothermal treatment, the as formed complex is thermolysed into LDH matrix. Reaction parameters such as reaction time, nature of the amino acid and reaction temperature are found to be crucial in controlling the final morphology. Sacnning electron microscopy, FTIR spectroscopy and X-Ray diffraction are adopted to investigate the evolution process of Ni precursor. The morphology variation are interpreted based on the amino-acid precursor nature and it’s decomposition pathways. Details of the synthesis and characterization of the nanomaterials generated therefrom will be presented.
Presentation: Poster at E-MRS Fall Meeting 2007, Symposium A, by Vanessa Prevot
See On-line Journal of E-MRS Fall Meeting 2007
Submitted: 2007-05-16 15:29 Revised: 2009-06-07 00:44