Pillaring of Layered Double Hydroxides Possessing Variable Layer Charge with Vanadium Polyoxoanions

1994 ◽  
Vol 371 ◽  
Author(s):  
F. Kooli ◽  
V. Rives ◽  
M.A. Ulibarri ◽  
W. Jones
Keyword(s):  
Surface Area ◽  
Layered Double Hydroxides ◽  
Layer Charge ◽  
Second Phase ◽  
Textural Characteristics ◽  
Al Content ◽  
Complete Exchange ◽  
Double Hydroxides ◽  
Charge Balancing ◽  
Variable Layer

AbstractA range of layered double hydroxides (LDHs) with Ni/Al and Mg/Al as the M(II)/M(III) cations and containing carbonate as the charge balancing anion have been synthesised. A variation in the M(II)/M(III) ratio between 2 and 6 has been attempted with the influence of the M(II)/M(III) ratio upon the subsequent exchange of carbonate by [V10O28]6- (at pH 4.5) examined. Complete exchange is obtained for all ratios, although the crystallinity of the products varies. For M(II)/M(III) ratios > 4, the product crystallinity is poor. In addition, a second phase is detected for all ratios. In the case of Ni/Al, the amount of vanadium incorporated is found to depend upon the Al content whereas for Mg/Al the amount incorporated is constant. Overall, the replacement of carbonate by decavanadate does not appear to have any significant effect on the textural characteristics (e.g. surface area or porosity) of the pillared products.

Tuneable ultra high specific surface area Mg/Al-CO3layered double hydroxides

2015 ◽  
Vol 44 (37) ◽  
pp. 16392-16398 ◽  
Author(s):  
Chunping Chen ◽  
Aunchana Wangriya ◽  
Jean-Charles Buffet ◽  
Dermot O'Hare
Keyword(s):  
Organic Solvent ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Layered Double Hydroxides ◽  
High Specific Surface Area ◽  
Double Hydroxides

We report the synthesis of tuneable ultra high specific surface area Aqueous Miscible Organic solvent-Layered Double Hydroxides (AMO-LDHs).

scholarly journals A Comparative Study on The Adsorption Behavior of Congo Red on to ZnAl and ZnCr Layered Double Hydroxides

2020 ◽  
Vol 9 (2) ◽  
pp. 108-116
Author(s):  
Tarmizi Taher ◽  
◽  
Nyanyu Ummu Hani ◽  
Neza Rahayu Palapa ◽  
Risfidian Mohadi ◽  
...  
Keyword(s):  
Experimental Data ◽  
Surface Area ◽  
Adsorption Kinetics ◽  
Layered Double Hydroxides ◽  
Congo Red ◽  
Adsorption Process ◽  
Bet Surface Area ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Double Hydroxides

In this work, two synthetic layered double hydroxides (LDH) consists of Zn2+ as M2+ cation with different M3+ cation, i.e., Al3+ and Cr3+ were used as an adsorbent for Congo Red removal aqueous solution. Both Zn-Al and Zn-Cr LDH were characterized by X-ray diffraction, FT-IR, and BET surface area analyzer. The effect of contact time, initial dye concentration, and temperature were evaluated in a batch technique in order to investigate the characteristic of Congo Red adsorption onto both adsorbents. The experimental data were assessed according to the parameter of adsorption kinetics, isotherm, and thermodynamics. The results of LDH characterization showed that Zn-Al LDH has a higher interlayer distance than Zn-Cr LDH, although Zn-Cr LDH has a higher surface area. The FT-IR analysis indicated the interlayer space of both Zn-Cr and Zn-Al LDH was dominated by CO32- as the interlayer anion species. The adsorption kinetics study of Congo Red on both LDH revealed that the adsorption process followed the pseudo-second-order model. For the adsorption isotherm, the experimental data fit well with the Freundlich model rather than the Langmuir model. The thermodynamic study indicated that the adsorption process that occurred on both adsorbents was spontaneous with exothermic nature.

Transition-metal-based layered double hydroxides tailored for energy conversion and storage

2018 ◽  
Vol 6 (1) ◽  
pp. 12-29 ◽  
Author(s):  
Rajkumar Patel ◽  
Jung Tae Park ◽  
Madhumita Patel ◽  
Jatis Kumar Dash ◽  
E. Bhoje Gowd ◽  
...  
Keyword(s):  
Energy Storage ◽  
Transition Metal ◽  
Energy Conversion ◽  
Surface Area ◽  
Layered Double Hydroxides ◽  
Energy Storage Materials ◽  
Storage Materials ◽  
Energy Conversion And Storage ◽  
Double Hydroxides ◽  
And Storage

Transition metal based layered double hydroxides are important energy storage materials. The overall performances of the electrodes are dependent on conductivity, crystallinity, morphology, and surface area.

scholarly journals Fumonisin B1 Interaction with Mg-Al and Mg-Fe Layered Double Hydroxides: Removal Efficiency and Mechanisms

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4344
Author(s):  
Jakub Matusik ◽  
Youjun Deng
Keyword(s):  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Layered Double Hydroxides ◽  
Lower Layer ◽  
Fumonisin B1 ◽  
Xrd Analysis ◽  
Layer Charge ◽  
Basal Spacing ◽  
Co Precipitation ◽  
Double Hydroxides

Mycotoxins in feed and food are highly toxic and pose a serious danger even at very low concentrations. The use of bentonites in animal diet can reduce toxin bioavailability. However, some mycotoxins like fumonisin B1 (FB1) form anionic species which excludes the use of negatively charged clays. Layered double hydroxides (LDH) with anion-exchange properties, in theory, can be perfect candidates to adsorb FB1. However, fundamental research on the use of LDH for mycotoxins removal is scarce and incomplete. Thus, the presented study was designed to explore such a possibility. The LDH materials with differing chemistry and layer charge were synthesized by co-precipitation both from metal nitrates and chlorides and were then tested for FB1 removal. XRD, FTIR, XPS, and chemical analysis were used for the LDH characterization and to obtain insight into the removal mechanisms. A higher adsorption capacity was observed for the Mg/Al LDH samples (~0.08–0.15 mol/kg) in comparison to the Mg/Fe LDH samples (~0.05–0.09 mol/kg) with no difference in removal efficiency between Cl and NO3 intercalated LDH. The adsorption capacity increased along with lower layer charge of Mg/Al and was attributed to the lower content of bonded carbonates and the increase of non-polar sites which led to matching between the adsorption domains of LDH with FB1. The FTIR analysis confirmed the negative effect of carbonates which hampered the adsorption at pH 7 and led to the highest adsorption at pH 5 (FB1 content ~15.8 ± 0.75 wt.%). The fast surface adsorption (1–2 min) was dominant and XRD analysis of the basal spacing indicated that no FB1 intercalation occurred in the LDH. The XPS confirmed a strong interaction of FB1 with Mg sites of LDH at pH 5 where the interaction with FB1 carboxylate moieties COO− was confirmed. The research confirmed a high affinity and selectivity of LDH structures towards anionic forms of FB1 mycotoxin.

scholarly journals Aqueous miscible organic layered double hydroxides as catalyst precursors for biodiesel synthesis

2020 ◽  
Vol 22 (10) ◽  
pp. 3117-3121
Author(s):  
Chunping Chen ◽  
Maxwell Greenwood ◽  
Jean-Charles Buffet ◽  
Dermot O'Hare
Keyword(s):  
Density Dependence ◽  
Surface Area ◽  
Layered Double Hydroxides ◽  
Sunflower Oil ◽  
Potassium Salt ◽  
Biodiesel Synthesis ◽  
Double Hydroxides

Surface area and basicity density dependence of base-catalysed transesterification of sunflower oil by potassium salt prepared AMO-layered double hydroxides.

scholarly journals Order and Disorder in Layered Double Hydroxides: Lessons Learned from the Green Rust Sulphate - Nikischerite Series.

2020 ◽  
Author(s):  
Knud Dideriksen ◽  
Laura Voigt ◽  
Marco Mangayayam ◽  
Simon H. J. Eiby ◽  
Case M. van Genuchten ◽  
...  
Keyword(s):  
Layered Double Hydroxides ◽  
Coherent Scattering ◽  
Lessons Learned ◽  
Nucleation Theory ◽  
Classical Nucleation Theory ◽  
Structural Characterisation ◽  
Al Content ◽  
Contaminant Remediation ◽  
Structural Coherence ◽  
Double Hydroxides

<div>Layered double hydroxides (LDHs) occur naturally and are synthesised for catalysis, drug</div><div>delivery and contaminant remediation. They consist of Me(II)-Me(III) hydroxide sheets</div><div>separated by hydrated interlayers and weakly held anions. Often, LDHs are nanocrystalline and</div><div>sheet stacking and Me(II)-Me(III) arrangement can be disordered, which influence reactivity and</div><div>complicate structural characterisation. We have used pair distribution function (PDF) analysis, to</div><div>provide detailed information about local and medium range order (< 9 nm), to determine the</div><div>structure of synthetic Fe(II)-Fe(III)/Al(III) LDH. The data are consistent with ordered Me(II)</div><div>and Me(III) in hydroxide sheets, where structural coherence along the c axis decreases with </div><div>increasing Al content. The PDF for Fe(II)-Al(III) LDH (nikischerite) is best matched by a</div><div>pattern for a single metal hydroxide sheet. Parallel to decreased structural coherence between</div><div>layers, coherence within layers decreased to ~6 nm for synthetic nikischerite. Thus, disorder</div><div>developed within and between the sheets, resulting in mosaic crystals with coherent scattering</div><div>domains decreasing in all directions. The high density of grain boundary terminations would</div><div>affect reactivity. Based on classical nucleation theory and the Kossel crystal growth model, we</div><div>propose that loss of structural coherence stems from increased supersaturation and the presence</div><div>of Al-hydroxides during formation of the Al-rich LDH</div>

scholarly journals Properties of calcium sulfoaluminate cement-based grouting materials with LiAl-layered double hydroxides slurries

2020 ◽  
Vol 29 ◽  
pp. 2633366X2092652 ◽  
Author(s):  
Haiyan Li ◽  
Xianping Wang ◽  
Xuemao Guan ◽  
Dinghua Zou
Keyword(s):  
Compressive Strength ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Layered Double Hydroxides ◽  
Setting Time ◽  
Hydration Products ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Double Hydroxides

In this study, LiAl-layered double hydroxides Lithium aluminum hydrotalcite (LiAl-LDH) with different specific surface area were prepared by the separate nucleation and aging steps (SNAS) method and then were employed to prepare calcium sulfoaluminate cement-based grouting material (CBGM) paste. The influence of LiAl-LDH slurries on fresh and hardened properties of the CBGM paste was investigated in terms of fluidity, stability, setting time, and compressive strength. Additionally, the hydration process and hydration products of the CBGM paste were characterized by hydration heat, X-ray diffraction, differential thermal analysis–thermogravimetry, and Fourier transform infrared analyses. The acquired results illustrated that LiAl-LDH with larger specific surface area led to a faster hydration rate at early age, a lower fluidity, a shorter setting time, and a higher stability. Furthermore, due to the crystal nucleation effect, the addition of LiAl-LDH slurries did not cause a new phase to form but changed the morphology and increased the amount of hydration products, yielding higher compressive strength.

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