Lead (Pb) contamination in water requires improved decontamination technologies. The addition of phosphate to precipitate Pb is a widely used method for remediating Pb in soil and water, though it has certain limitations. This study focuses on novel 3D mesoporous layered double hydroxide (LDH) sorbents functionalized with phosphate anions for Pb removal from contaminated waters.
View Article and Find Full Text PDFSlow-release fertilizers (SRFs) form the core of innovative strategies in sustainable agriculture. Layered Double Hydroxides (LDH), known for their high capacity to sequester plant nutrients, especially phosphate, are emerging as promising candidates for SRF synthesis. The phosphate release properties of MgAl LDH (with a targeted Mg/Al ratio of 2.
View Article and Find Full Text PDFNanocomposites based on hydrozincite-TiO and copper-doped HZ-xCu-TiO (x = 0.1; 0.25; 0.
View Article and Find Full Text PDFThis study describes the behavior of potential slow-release fertilizers (SRF), prepared by the mechanochemical activation of calcined Mg₂Al-CO₃ or Mg₂Fe-CO₃ layered double hydroxides (LDH) mixed with dipotassium hydrogen phosphate (K₂HPO₄). The effects of LDH thermal treatment on P/K release behavior were investigated. Characterizations of the inorganic composites before and after release experiments combined X-Ray diffraction (XRD), Fourier-transform infra-red spectroscopy (FTIR), solid-state nuclear magnetic resonance (NMR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX).
View Article and Find Full Text PDFLayered double hydroxides (LDHs), especially (doped) with transition metals, as well as nanohybrid and 2D materials derived from these structures, are interesting materials due to their catalytic and electrochemical properties. Their reactivity is determined by the atomic level distribution of the transition metal in the LDH cation layer, which is essential to control the design of LDHs with optimized properties. However, low crystallinity, absence of long range order, and/or isoelectronic ions often prevent atomic level structural characterization.
View Article and Find Full Text PDFThis review highlights the current research on the interactions between biological cells and Layered Double Hydroxides (LDH). The as-prepared biohybrid materials appear extremely attractive in diverse fields of application relating to health care, environment and energy production. We describe how thanks to the main features of biological cells and LDH layers, various strategies of assemblies can be carried out for constructing smart biofunctional materials.
View Article and Find Full Text PDFTriketones, derived chemically from a natural phytotoxin (leptospermone), are a good example of allelochemicals as lead molecules for the development of new herbicides. Targeting a new and key enzyme involved in carotenoid biosynthesis, these latest-generation herbicides (sulcotrione, mesotrione and tembotrione) were designed to be eco-friendly and commercialized fifteen-twenty years ago. The mechanisms controlling their fate in different ecological niches as well as their toxicity and impact on different organisms or ecosystems are still under investigation.
View Article and Find Full Text PDFBayerite was treated under hydrothermal conditions (120, 130, 140, and 150 °C) to prepare a series of layered double hydroxides (LDHs) with an ideal composition of ZnAl4(OH)12(SO4)0.5·nH2O (ZnAl4-LDHs). These products were investigated by both bulk techniques (powder X-ray diffraction (PXRD), transmission electron microscopy, and elemental analysis) and atomic-level techniques ((1)H and (27)Al solid-state NMR, IR, and Raman spectroscopy) to gain a detailed insight into the structure of ZnAl4-LDHs and sample composition.
View Article and Find Full Text PDFHierarchically porous biocompatible Mg-Al-Cl-type layered double hydroxide (LDH) composites containing aluminum hydroxide (Alhy) have been prepared using a phase-separation process. The sol-gel synthesis allows for the hierarchical pores of the LDH-Alhy composites to be tuned, leading to a high specific solid surface area per unit volume available for high-molecular-weight protein adsorptions. A linear relationship between the effective surface area, SEFF, and loading capacity of a model protein, bovine serum albumin (BSA), is established following successful control of the structure of the LDH-Alhy composite.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
February 2015
A soft chemical process was successfully used to immobilize Pseudomonas sp. strain ADP (ADP), a well-known atrazine (herbicide) degrading bacterium, within a Mg2Al-layered double hydroxide host matrix. This approach is based on a simple, quick and ecofriendly direct coprecipitation of metal salts in the presence of a colloidal suspension of bacteria in water.
View Article and Find Full Text PDFDecatungstate W10O32(4-) was efficiently intercalated between the layers of three-dimensionally ordered macroporous Mg2Al-layered double hydroxide. The structural and textural properties of as-prepared intercalated compound were characterized using different solid-state characterization techniques such as X-ray powder diffraction, FTIR and Raman spectroscopies and electronic microscopy. The photocatalytic properties of immobilized W10O32 (4-) within Mg2Al structure were investigated using 2-(1-naphthyl) acetamide (NAD) as a model of pesticide.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
December 2013
A natural Cameroonian smectite-type clay (SaNa) was exchanged with cationic surfactants, namely cetyltrimethylammonium (CTA) and didodecyldimethyl ammonium (DDA) modifying its physico-chemical properties. The resulting organoclays that have higher adsorption capacity for mesotrione than the pristine SaNa clay, have been used as modifiers of glassy carbon electrode for the electrochemical detection of this herbicide by square wave voltammetry. The stripping performances of SaNa, SaCTA and SaDDA modified electrodes were therefore evaluated and the experimental parameters were optimized.
View Article and Find Full Text PDFAerogels of layered double hydroxides were prepared by a simple and eco-friendly method involving a quick coprecipitation followed by supercritical CO(2) drying. Such aerogels display high surface areas and enhanced adsorption behavior.
View Article and Find Full Text PDFTo mimic the role of hydroxide minerals and their humic complex derivatives on the biodegradability of pesticides in soils, synthetic Mg(R)Al Layered Double Hydroxides (LDH) and Mg(R)Al modified by Humic substances (LDH-HA) were prepared for various R values (2, 3 and 4) and fully characterized. Adsorption properties of LDH and LDH-HA toward Pseudomonas sp. strain ADP were evaluated.
View Article and Find Full Text PDFColloidal crystals of polystyrene (PS) beads self-assembled on Pt electrode were used as a sacrificial template to electrosynthesis thin films of macroporous Layered Double Hydroxides (LDH). Such nanostructured materials display a high internal surface area and porosity leading to enhanced electrochemical performance.
View Article and Find Full Text PDFHemoglobin was immobilized in Mg(2)Al-Layered Double Hydroxides (LDH) by coprecipation method at pH 9.0. Interactions between Hb and LDH particles were investigated by X-ray diffraction patterns, FTIR, UV-vis, circular dichroism, and fluorescence spectroscopies.
View Article and Find Full Text PDFAn amperometric sensor based on Ni(1-x)Al(x)(OH)(2)NO(3x).nH(2)O layered double hydroxide (LDH) has been developed for the electrochemical analysis in one step of two herbicides: glyphosate (N-(phosphonomethyl)glycine, Glyp) and glufosinate ((DL-homoalanine-4-yl)-methylphosphinic acid, Gluf). NiAl-LDH was prepared by coprecipitation or by electrodeposition at the Pt electrode surface.
View Article and Find Full Text PDFThe possible role of structural iron in clays to promote direct electron transfer of hemoglobin (Hb) was investigated. Clays containing different amounts of iron situated in octahedral or tetrahedral sites have been used to modify glassy carbon electrodes: nontronite, synthetic montmorillonite, and saponite. A synthetic montmorillonite containing non-iron impurities was used as a reference.
View Article and Find Full Text PDFThis paper presents the preparation and characterization of hybrid hydrotalcite-type layered double hydroxides (Zn1-xAlx(OH)2HBSx.nH2O, with x=0.33) where HBS is the 4-phenol sulfonate, with a detailed analysis of the grafting process of this organic entity onto the host lattice.
View Article and Find Full Text PDFThe fate of pesticides in the environment is strongly related to the soil sorption processes that control not only their transfer but also their bioavailability. Cationic (Ca-bentonite) and anionic (Layered Double Hydroxide) clays behave towards the ionisable pesticide atrazine (AT) sorption with opposite tendencies: a noticeable sorption capacity for the first whereas the highly hydrophilic LDH showed no interactions with AT. These clays were modified with different humic acid (HA) contents.
View Article and Find Full Text PDFFormation of new bio-nanohybrid material was obtained by immobilization of alkaline phosphatase within a Mg(2)Al LDH by "soft chemistry" coprecipitation synthesis, resulting in an original spongy gel-like morphology allowing the preservation of the enzyme structure and activity even at low pH values thanks to the buffering property of the basic host structure.
View Article and Find Full Text PDFA biomineralization process based on the promotion of precipitating agent by the urea-urease enzymatic system is developed to prepare ZnAl layered double hydroxide materials and the effects of the enzymatic reaction parameters on the structural and textural properties of the materials are investigated on the basis of XRD and EM analysis.
View Article and Find Full Text PDFMgAl-layered double hydroxides with different interlayer anions (nitrate, carbonate and chloride) were evaluated for their abilities to adsorb the organic pesticide glyphosate (N-phosphonomethyl glycine, Gly). The adsorption isotherms of Gly on layered double hydroxides (LDHs) nitrate were described by the Langmuir equation at lower equilibrium concentration of Gly (C(e)<1.0 mmol/L), and the Gly adsorption capacity on LDHs increased with the layer charge density, i.
View Article and Find Full Text PDFChem Commun (Camb)
November 2001
Adsorbed vs. intercalated MCPA (4-chloro-2-methylphenoxyacetic acid) in highly hydrated clays taken as a soil model were clearly distinguished by 1H HR MAS NMR; adsorbed herbicide gave sharp signals indicating high mobility while intercalated herbicide gave very wide unresolved spectra due to its strong interaction with the solid matrix.
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