Sol-gel route to niobium pentoxide

Journal Article · · Chemistry of Materials; (USA)

DOI:https://doi.org/10.1021/cm00014a026· OSTI ID:5563711

Griesmar, P; Papin, G; Sanchez, C; Livage, J ^[1]

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1. Universite Pierre et Marie Curie, Paris (France)

Niobium pentoxide powders were synthesized via the sol-gel route. Monolithic gels can be reproducibly obtained when the hydrolysis of niobium alkoxides Nb(OR){sub 5} is performed in the presence of acetic acid. This carboxylic acid reacts with the alkoxide and leads to the formation of new Nb(OR){sub 5{minus}x}(OAc){sub x} (0 < x < 1) precursors. Therefore the whole hydrolysis-condensation process is modified. The different steps of the synthesis, from the molecular precursor Nb(OPent{sup n}){sub 5} (Pent{sup n} is a normal pentyl group) to the crystalline oxide were characterized by {sup 1}H NMR, {sup 13}C CP MAS NMR, and infrared spectroscopies, thermal analysis, and X-ray diffraction. Xerogels are obtained after drying the gel at 80{degree}C. They are made of an oxo-polymer network in which some alkoxy groups and acetate ligands remain bonded to niobium. These organic groups are removed upon heating in air leading to the crystallization of T-Nb{sub 2}O{sub 5} at around 550{degree}C.

• OSTI ID: 5563711
• Journal Information: Chemistry of Materials; (USA), Journal Name: Chemistry of Materials; (USA) Vol. 3:2; ISSN CMATE; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
&amp; Refractories-- Preparation &amp; Fabrication
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL PREPARATION
COHERENT SCATTERING
DIFFERENTIAL THERMAL ANALYSIS
DIFFRACTION
GRAVIMETRIC ANALYSIS
INFRARED SPECTRA
MAGNETIC RESONANCE
NIOBIUM COMPOUNDS
NIOBIUM OXIDES
NUCLEAR MAGNETIC RESONANCE
OXIDES
OXYGEN COMPOUNDS
POWDERS
QUANTITATIVE CHEMICAL ANALYSIS
REFRACTORY METAL COMPOUNDS
RESONANCE
SCATTERING
SOL-GEL PROCESS
SPECTRA
SYNTHESIS
THERMAL ANALYSIS
THERMAL GRAVIMETRIC ANALYSIS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION