Novel route for layered double hydroxides preparation by enzymatic decomposition of urea

Vial, Stéphanie; Prevot, Vanessa; Forano, Claude

doi:10.1016/j.jpcs.2006.01.024

Cited by 30 publications

(17 citation statements)

References 23 publications

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“…This difference may be related to the layered structure of the hydroxide and the nature of molecules or ions incorporated from the urea decomposition. In fact as urea decomposes at elevated temperature, it produces numerous ions and molecules such as: CNO − , HNCO, CO 2; HCO 3 − , NH 4 + , and NH 3 [13,20,23]. This complex decomposition scenario can cause the precipitation of metals in compositions other than hydroxides or the incorporation of these various ions within the interlayer spacing of the hydroxide.…”

Section: Resultsmentioning

confidence: 99%

“…Even in an excess of hydroxide, this typically results in a solution containing a wide particle size distribution and particles with low tap density [13,23]. The thermal decomposition of urea (reaction scheme below) takes place at temperatures greater than 90°C [4,13,17,20,23],…”

Section: Introductionmentioning

confidence: 99%

“…In the traditional coprecipitation method, the saturation of the precipitating agent is achieved rapidly leading to the continuous nucleation, growth, and aggregation of particles, resulting in a precipitate with a wide size distribution [23].…”

Section: Introductionmentioning

confidence: 99%

“…The decomposition of urea was previously demonstrated to be a successful precipitation route to metal carbonates [23], various hydroxide phases [4,13] and, recently, Recham et al used urea decomposition for the hydrothermal synthesis of LiFePO 4 [17]. The main difficulty with the hydroxides, which were prepared previously utilizing the thermal decomposition of urea, is the complex phase obtained from the resultant product.…”

Section: Introductionmentioning

confidence: 99%

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A novel coprecipitation method towards the synthesis of NixMnxCo(1–2x)(OH)2 for the preparation of lithium metal oxides

Rodrigues

Wontcheu

MacNeil

2011

J Solid State Electrochem

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A series of mixed metal hydroxide (Ni x Mn x Co (1-2x) (OH) 2 ) precursors for the preparation of lithiated mixed metal oxides (LiNi x Mn x Co (1-2x) O 2 ) were prepared using a novel coprecipitation approach based on the thermal decomposition of urea. Three different methods were used to achieve the temperature required to decompose urea and subsequently precipitate the hydroxides. The first two methods consisted of either a hydrothermal or microwaveassisted hydrothermal synthesis at 180°C and elevated pressures. The final method was an aqueous reflux at 100°C. A complete series (x=0.00-0.50) was prepared for each method and fully characterized before and after converting the materials to lithiated metal oxides (LiNi x Mn x Co (1-2x) O 2 ). We observed the formation of a complex structure after the coprecipitation of the hydroxides. Scanning electron micrographs images demonstrate that the morphology and particle size of the hydroxide particles varied significantly from x=0.00-0.50 under hydrothermal synthesis conditions. There is also a significant change in particle morphology as the urea decomposition method is varied. The X-ray diffraction profiles of the oxides synthesized from these hydroxide precursors all demonstrated phase pure oxides that provided good electrochemical performance.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A novel coprecipitation method towards the synthesis of NixMnxCo(1–2x)(OH)2 for the preparation of lithium metal oxides

Rodrigues

Wontcheu

MacNeil

2011

J Solid State Electrochem

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“…[1] Hydrotalcite (HT) or Mg 6 Al 2 (OH) 2 has been used as a catalyst in dehydrochlorination and recovery of hydrochloric acid [2,3] and decomposition of urea. [4] HT has already found use in pharmaceutical industries as a drug carrier because of its biocompatibility and the swelling properties. The swelling of HT nanocomposite hydrogels has been known to cause uncharged drug solute released through the gel easily.…”

Section: Introductionmentioning

confidence: 99%

The conversion of an organometallic compound into an intercalated thin‐layer amorphous structure

Othman

Fernando

Kim

2009

Applied Organom Chemis

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A thin alumina-hydrotalcite (Al-HT) film was fabricated from the synthesized boehmite and HT sol samples. The sols were a Newtonian fluid within 12 h of the sol synthesis and pseudo-plastic flow thereon. Co-precipitated HT demonstrated poorly crystallized periclase and spinel structures and apparent doublet peak of hydrotalcite at 2θ = 39-44• , indicative of a disordered structure. The heated Al-HT sample demonstrated highly amorphous structure with single hydrotalcite peak but barely observed γ -alumina and γ -boehmite phases. The exfoliation of the spinel, gibbsite and periclase in the Al-HT was caused by the intercalation of boehmite into the HT layers that impeded the formation of the oxides phases.

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Nano/Microporous Materials: Nanostructured Layered Double Hydroxides

Leroux¹,

Pr��vot²

2005

Encyclopedia of Inorganic Chemistry

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This review summarizes developments in nanostructured layered double hydroxide (LDH) materials for the period 2004–2007. Particular attention is paid to synthesis aspects, including coprecipitation, urea decomposition, sol‐gel processing and derivative methods as well as the generation of functional materials through delamination either from solvent solution or in situ within a polymer. Coating processes, illustrated by the heterogeneous growth of nanorods onto LDH surfaces, is distinguished from particle nanostructuration. In addition, nanostructuration from LDH frameworks is described for iron‐based oxides and other metal oxides in which catalytic, magnetic, or energy‐storage properties are discussed. Other examples of nanostructuration, such as complex encapsulation, are demonstrated not only with different complexes, such as polyoxometallates and porphyrines but also with rare earth and quantum dot materials, where interest is focused on luminescent and optical properties. Additionally, drug encapsulation and/or release, gene‐reservoir applications, and incorporation of DNA and bioinorganic enzymes into LDH assemblies nicely illustrate biologically related uses of LDH nanoplatelets. Finally, reactions occurring within LDH interlayer spaces are described, and the role of LDH framework as a nanoreactor is illustrated by in situ polymerization of conjugated polymers and thermoplastics. LDH materials can also be used as sacrificial templates for fabricating nanosized polymers and for the synthesis of carbon replica and carbon fibers.

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Novel route for layered double hydroxides preparation by enzymatic decomposition of urea

Cited by 30 publications

References 23 publications

A novel coprecipitation method towards the synthesis of NixMnxCo(1–2x)(OH)2 for the preparation of lithium metal oxides

A novel coprecipitation method towards the synthesis of NixMnxCo(1–2x)(OH)2 for the preparation of lithium metal oxides

The conversion of an organometallic compound into an intercalated thin‐layer amorphous structure

Nano/Microporous Materials: Nanostructured Layered Double Hydroxides

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