Pristine Layered Double Hydroxides Research Articles

Improving humidity sensor performance through phenylphosphonic acid-intercalated layered double hydroxide

This work delineates the development of humidity sensors utilizing layered double hydroxides (LDH) intercalated with phenylphosphonic acid (PPA), characterized by strong coordination and hydrophilicity. Following the meticulous synthesis of pristine LDH and PPA-LDH, sensor fabrication and comprehensive performance evaluation were conducted. Morphological analysis through SEM and TEM revealed a layered, thin PPA-LDH structure, augmenting the surface area for interaction with water. Density functional theory (DFT) computations elucidated the enhanced sensing mechanism, demonstrating that PPA intercalation significantly amplifies the adsorption energy of water molecules at metal sites, thereby facilitating proton and charge transfer. At 85 % relative humidity, the PPA-LDH sensor manifested an astonishing response of 4392.3 %, showcasing exceptional cyclic stability and rapid response/recovery times of 23 and 10 s, respectively. Comparative analysis with existing technologies underscored the superior sensitivity and response characteristics of the PPA-LDH sensor. The study concludes that PPA-intercalated LDH notably enhances humidity sensing capabilities, furnishing a material with heightened sensitivity and stability for the forthcoming generation of humidity sensors.

NiAl LDH nanosheets based on Ag nanoparticles-decoration and alkali etching strategies for high performance supercapacitors

Layered double hydroxides (LDHs) represent a category of two-dimensional layered intercalation materials, showing significant potential as electrode materials for the production of high-energy-density supercapacitors due to their tunable composition, ease of synthetic modification, and low cost. Here, we constructed alkali-etched NiAl LDH-OH nanosheets/Ag nanoparticles (NPs) composite material (Ag@NiAl LDH-OH) for high-performance supercapacitors through a simple solvent-thermal reaction. The alkali treatment is employed to selectively etch some Al3+ ions, generating cation vacancies as active sites for energy storage. Additionally, under the simultaneous influence of strong alkalis and vacancies, the interlayer spacing of LDHs expands, aiding in the promotion of interlayer ion mobility. Meanwhile, the decoration of silver nanoparticles ensures excellent electron conductivity in the NiAl-LDH-OH nanosheets, thereby facilitating improved utilization of the active substance and achieving outstanding rate performance. The Ag@NiAl LDH-OH electrode, when prepared, demonstrates a significant increase in specific capacitance, reaching 1790 F g−1 at a current density of 1 A g−1. This represents approximately 7 times the specific capacitance of the pristine NiAl LDH electrode, with a capacity retention of 79 % even under a high current density of 20 A g−1. Moreover, the assembled asymmetric supercapacitor (ASC) attains a maximum energy density of 138.25 Wh kg−1 at a power density of 700 W kg−1, maintaining 81 % of its initial specific capacitance after 20000 cycles. This research introduces novel pathways for advancing high-energy-density SCs.

Selective Covalent Basal Plane Modification as a Probe of Hydroxide Ion Conduction Pathways in Magnesium Aluminum Layered Double Hydroxides.

Understanding ionic conduction in layered double hydroxides (LDHs) is a crucial step towards utilizing them as solid, hydroxide ion-conducting electrolytes in energy conversion applications. We selectively modified the interlayer and external surfaces of MgAl LDHs with tris(hydroxymethyl)aminomethane (TRIS) ligands. By adjusting the concentration of the TRIS surface modifier, the LDH basal plane surfaces could be functionalized everywhere (internally and externally) or only externally. External modification resulted in loss of OH-conductivity compared to pristine LDHs, confirming that external platelet surfaces are the primary ion conduction pathway.

Electron Accumulation Induced by Electron Injection-Incomplete Discharge on NiFe LDH for Enhanced Oxygen Evolution Reaction.

Optimizing the local electronic structure of electrocatalysts can effectively lower the energy barrier of electrochemical reactions, thus enhancing the electrocatalytic activity. However, the intrinsic contribution of the electronic effect is still experimentally unclear. In this work, the electron injection-incomplete discharge approach to achieve the electron accumulation (EA) degree on the nickel-iron layered double hydroxide (NiFe LDH) is proposed, to reveal the intrinsic contribution of EA toward oxygen evolution reaction (OER). Such NiFe LDH with EA effect results in only 262mV overpotential to reach 50 mAcm-2, which is 51mV-lower compared with pristine NiFe LDH (313mV), and reduced Tafel slope of 54.8mVdec-1 than NiFe LDH (107.5mVdec-1). Spectroscopy characterizations combined with theoretical calculations confirm that the EA near concomitant Vo can induce a narrower energy gap and lower thermodynamic barrier to enhance OER performance. This study clarifies the mechanism of the EA effect on OER activity, providing a direct electronic structure modulation guideline for effective electrocatalyst design.

Recent Advancement in Quantum Dot Modified Layered Double Hydroxide towards Photocatalytic, Electrocatalytic, and Photoelectrochemical Applications

AbstractLayered double hydroxides (LDHs) is a category of 2D materials that possess excellent physicochemical properties for enhancing photocatalytic (PC), electrocatalytic (EC), and photoelectrochemical (PEC) performances. However, pristine LDH encounters challenges like sluggish charge–carrier mobility, high rate of electron–hole recombination, low conductivity, and tendency to agglomerate, making them unsuitable for practical applications. Therefore, modifications such as composite preparations, co‐catalyst integration, semiconductor coupling, and ternary heterostructure engineering have been explored to disclose new possibilities for LDHs in PC, EC, and PEC applications. In the realm of semiconducting materials aimed at enhancing LDH productivity, quantum dots (QDs) i. e., 0D materials have proven to be effective due to their advantages, including abundant reserves, affordability, and environmental friendliness. This review explores the role of QDs as interlayer support, co‐catalyst, mediator, semiconductor, and sensitizer in QDs@LDH heterostructures to achieve superior photocatalytic activities. These QD‐infused heterostructures also deliver improved EC and PEC water–splitting performance coupled with long–term stabilities. Additionally, this review delves into characterization techniques, intrinsic structural features, and designing of the QD@LDH heterostructures. Future scopes and challenges in constructing and cutting–edge theoretical anticipations of QD@LDH are also discussed. This review may be a guiding light to a sustainable approach to outperform QD‐modified LDH for versatile catalysts.

Thermal Evolution of NiFe-NO3 LDH and Its Application in Energy Storage Systems

In this work, the performances of nickel iron layered double hydroxides (LDH) with the nitrate anion at the interlayer (NiFe-NO3) for the manufacture of anodes for lithium-ion batteries have been tested before and after its sintering at different temperatures. After synthesis, the material was thermally analyzed in a range 30–1250 °C, showing a mass loss occurring in three different consecutive steps leading to a total mass decrease of ~30 mass%. Following thermogravimetric analysis (TGA), four samples were prepared by annealing at four different temperatures: one of the four did not undergo a thermal treatment (NiFe-0), while the remaining three were annealed at 250 °C, 360 °C, and 560 °C for 6 h (NiFe-250, NiFe-360, and NiFe-560). All materials where completely characterized via FE-SEM, PXRD, and FT-IR. The pristine LDH material showed some structural and compositional changes for growing temperatures, starting from the typical turbostratic hexagonal structure through a mixture of amorphous metal oxides and finally to the stoichiometric oxides FeNi2O4 and NiO. The as-obtained materials were mixed with carbon black (C65) and sodium alginate and tested as electrodes in Swagelok half cells in LP30 vs. metallic Li to perform CV and GCPL analysis. The electrochemical tests showed that the performances of NiFe-0, both in terms of stability and specific capacity, are not so different from the one of the NiFe-560, even if the Ni mass% in the former is lower than in the NiFe-560. This phenomenon could be explained by assuming a combined mechanism of reaction involving both intercalation and conversion.

CQDs-interspersed floral CdS/NiAl-LDH heterojunction towards efficient photoreduction of CO2-to-CO

A series of hierarchical flower-like CdS/carbon quantum dots/NiAl-LDH (CCL) photocatalyst have been successfully prepared to achieve efficient conversion of CO2-to-CO via a simple yet effective hydrothermal method. In the CCL, interspersed-CQDs not only increase the number of reactive sites but also reduce inner electronic impedance with the assistance of light reflecting-scattering effect. This significantly improves electron migration efficiency and inhibits the recombination of photoinduced electron-holes pairs. Without any sacrificial agent or photosensitizer, the sample of CCL-1 exhibits the highest CO evolution rate of 7.04 μmol·g−1·h−1 in water under simulated sunlight illumination with a large specific surface area (129.15 m2 g−1) and an appropriate CQDs content of 15.2 wt%, which is 12.8- and 11.2-fold higher than those of pristine LDH, pure CdS, and many previously reported LDH-based counterparts. A type-Ⅱ interfacial charge transfer mechanism is proposed, where electrons migrate rapidly from CdS to LDH with highly-interspersed CQDs as unhindered electron conduction bridges. The present work outlines a simple and controllable LDH-based heterojunction, which give rise to superior photocatalytic activity for CO2 photoreduction.

Surface-Modified LDH Nanosheets with High Dispersibility in Oil for Friction and Wear Reduction.

Surface and interfacial engineering of nanomaterials is essential for improving dispersion stability in liquids. In this study, we report that oleic acid (OA)- and stearic acid (SA)-functionalized layered double hydroxide (LDH) nanosheets as lubricant additives can achieve high dispersion and reduce friction and wear. LDH is a typical layered structure, and OA and SA are long-chain organic molecules that are not only compatible with base oils but also act as friction-reducing agents. The OA and SA molecules were branched onto ZnMgAl LDH nanosheets using dehydration condensation between the exposed OH groups on the surface of LDH and the COOH groups on the OA and SA molecules. Compared with that of the pristine ZnMgAl LDH, the dispersion of OA-ZnMgAl LDH and SA-ZnMgAl LDH was significantly improved. The surface-modified LDH exhibited superior tribological properties and great stability due to the synergistic lubrication effect between OA, SA, and LDH. Even at an ultralow concentration (0.15 wt %), the coefficient of friction and wear volume were reduced by ∼65 and ∼99%, respectively, compared to those of the base oil. Due to the green and simple synthesis method and excellent tribological properties, surface-functionalized LDH has enormous possibilities for future industrial applications.

Layered double hydroxide-based electrode materials derived from metal-organic frameworks: synthesis and applications in supercapacitors.

Metal-organic frameworks (MOFs) have emerged as promising electrode materials for supercapacitors (SCs) due to their highly porous structures, tunable chemical compositions, and diverse morphologies. However, their applications are hindered by low conductivity and poor cycling performance. A novel approach for resolving this issue involves the growth of layered double hydroxides (LDHs) using MOFs as efficient templates or precursors for electrode material preparation. This method effectively enhances the stability, electrical conductivity, and mass transport ability of MOFs. The MOF-derived LDH exhibits a well-defined porous micro-/nano-structure, facilitating the dispersion of active sites and preventing the aggregation of LDHs. Firstly, this paper introduces synthesis strategies for converting MOFs into LDHs. Subsequently, recent research progress in MOF-derived LDHs encompassing pristine LDH powders, LDH composites, and LDH-based arrays, along with their applications in SCs, is overviewed. Finally, the challenges associated with MOF-derived LDH electrode materials and potential solutions are discussed.

Rapid and efficient removal of methylene blue dye from aqueous solutions using extract-modified Zn–Al LDH

Environmental pollution, particularly water pollution caused by organic substances like synthetic dyes, is a pressing global concern. This study focuses on enhancing the adsorption capacity of layered double hydroxides (LDHs) to remove methylene blue (MB) dye from water. The synthesized materials are characterized using techniques like FT-IR, XRD, SEM, TEM, TGA, EDS, BET, BJH, AFM, and UV–Vis DRS. Adsorption experiments show that Zn–Al LDH@ext exhibits a significant adsorption capacity for MB dye compared to pristine LDH. In addition, Zn–Al LDH@ext shows a significant increase in stability, which is attributed to the presence of phenolic compounds in the extract and the interactions between the functional groups of the extract and LDH. The pH and adsorbent dosage optimizations show that pH 7 and 0.7 g of Zn–Al LDH@ext are optimal conditions for efficient MB removal. The study assessed adsorption kinetics through the examination of Langmuir, Freundlich, and Temkin isotherms. Additionally, four kinetic models, namely pseudo-first-order, pseudo-second-order, intraparticle diffusion, and Elovich, were analyzed. The results indicated that the Temkin isotherm (R2 = 0.9927), and pseudo-second-order (R2 = 0.9999) kinetic provided the best fit to the experimental data. This study introduces a novel approach to enhance adsorption efficiency using modified LDHs, contributing to environmentally friendly and cost-effective water treatment methods.

Tunable capacitive charge storage of NiCoLDH@rGO for high-energy capacitor: Performance of flexible solid-state capacitor

The compositionally tunned pristine nickel cobalt layered double hydroxides (NiCoLDHs) and NiCoLDH@reduced graphene-oxide (NiCoLDH@rGO) composites generated via the simple single-pot solvothermal method. The synthesized NiCoLDH and the NiCoLDH@rGO composites were characterized through powder X-ray diffraction (XRD), Raman spectroscopy, Fourier transformed infra-red (FT-IR) spectroscopy, scanning electron microscope (SEM) equipped with energy dispersive X-ray analysis (EDAX), high-resolution transmission electron microscope (HR-TEM), and X-ray photoelectron spectroscopy (XPS) techniques. The XRD, Raman and FT-IR data confirmed the formation of the NiCoLDH with presence of carbonate and nitrate ions in the basal space. Enhanced basal length was observed for the NiCoLDH@rGO composites. The three-electrode system was constructed to analyse the cyclic voltammetry and Galvanostatic charge-discharge studies in 1 M KOH confirmed that the pristine LDHs and the composites are electrochemically active, and the capacity could be tuned by varying (Ni2+/Co3+) mole ratio or the rGO content. The charge storage kinetics in NiCoLDH@rGO was performed through Dunn's approaches and the Power Law, affirmed as the (Ni2+/Co3+) ratio or the rGO content is increased in the composite the capacitive contribution is increased for the charge storage. The NC@RG10 (NiCoLDH with 10 wt% rGO) composite electrode could deliver an enhanced specific capacity of 963C g−1 at a current rate of 1.5 A g−1. Consequently, pristine LDH or composites as positive electrode and rGO as negative electrode was fabricated using the CR-2032 coin-type hybrid capacitor. The laboratory prototype pristine hybrid capacitor (NiCoLDH|1 M KOH|rGO) delivered an enhanced specific energy of 56 Wh kg−1 at specific power of 810 W kg−1, whereas the composite hybrid device (NC@RG10|1 M KOH|rGO) having NC@RG10 electrode delivered an enhanced specific energy of 166 Wh kg−1 at specific power of 638 W kg−1. The NC@RG10 composite-based hybrid device exhibited excellent stability with coulombic efficiency as high as 99 % even at the 10,000th charge−discharge cycle. Reduced aggregation and enhanced conductivity leading to significant capacitive contribution in the NC@RG10 composite is due to the existence of rGO and responsible for the excellent charge storage performance. The fabricated hybrid capacitor powered a red LED on a single charge for 40 min. Fascinatingly, a flexible solid-state hybrid capacitor was also fabricated that delivered an impressive specific energy of 28 Wh kg−1 at a specific power of 553 W kg−1 at a 180° bent angle.

Intrabasal Plane Defect Formation in NiFe Layered Double Hydroxides Enabling Efficient Electrochemical Water Oxidation.

Defect engineering has proven to be one of the most effective approaches for the design of high-performance electrocatalysts. Current methods to create defects typically follow a top-down strategy, cutting down the pristine materials into fragmented pieces with surface defects yet also heavily destroying the framework of materials that imposes restrictions on the further improvements in catalytic activity. Herein, we describe a bottom-up strategy to prepare free-standing NiFe layered double hydroxide (LDH) nanoplatelets with abundant internal defects by controlling their growth behavior in acidic conditions. Our best-performing nanoplatelets exhibited the lowest overpotential of 241 mV and the lowest Tafel slope of 43 mV/dec for the oxygen evolution reaction (OER) process, superior to the pristine LDHs and other reference cation-defective LDHs obtained by traditional etching methods. Using both material characterization and density functional theory (DFT) simulation has enabled us to develop relationships between the structure and electrochemical properties of these catalysts, suggesting that the enhanced electrocatalytic activity of nanoplatelets mainly results from their defect-abundant structure and stable layered framework with enhanced exposure of the (001) surface.

Synergistic approach for synthesis of functionalized biochar for efficient adsorption of Lopinavir from polluted water

The COVID-19 pandemic has led to a significant increase in antibiotic consumption, along with a 70% rise in antiviral drug concentrations in aquatic ecosystems. For the effective adsorption of antibiotics, biochar was modified by incorporating layered double hydroxide (LDH) through hydrothermal method. The results showed that LDH provides additional hydroxyl groups, positive surface charges and ion exchange. Whereas biochar component provides a larger specific surface area (467.8 m2/g). Batch adsorption experiments of biochar @ layered double hydroxide (BC@LDH) showed enhanced adsorption performance (832.9 mg/g), compared to pristine LDH (420.3 mg/g) and unmodified biochar (548.5 mg/g). Adsorption data were best interpreted (R2 = 0.99) by pseudo second order, Freundlich, and Temkin isotherm models. Adsorption was a synergism of LDH and biochar physiochemical properties, whereas pore-filling was the primary mechanism. The recyclability of BC@LDH confirmed its good structural stability. This study introduces a sustainable and efficient method for synthesizing a versatile adsorbent with superior antibiotic removal.

Defective Nickel–Iron Layered Double Hydroxide for Enhanced Photocatalytic NO Oxidation with Significant Alleviation of NO2 Production

Photocatalysis offers a sustainable means for the oxidative removal of low concentrations of NOx (NO, NO2, N2O, N2O5, etc.) from the atmosphere. Layered double hydroxides (LDHs) are promising candidate photocatalysts owing to their unique layered and tunable chemical structures and abundant surface hydroxide (OH−) moieties, which are hydroxyl radical (OH) precursors. However, the practical applications of LDHs are limited by their poor charge-separation ability and insufficient active sites. Herein, we developed a facile N2H4-driven etching approach to introduce dual Ni2+ and OH− vacancies (Niv and OHv, respectively) into NiFe-LDH nanosheets (hereafter referred to as NiFe-LDH-et) to facilitate improved charge-carrier separation and active Lewis acidic site (Fe3+ and Ni2+ exposed at OHv) formation. In contrast to inert pristine LDH, NiFe-LDH-et actively removed NO under visible-light illumination. Specifically, Ni76Fe24-LDH-et etched with 1.50 mmol·L−1 N2H4 solution removed 32.8% of the NO in continuously flowing air (NO feed concentration: ∼500 parts per billion (ppb)) under visible-light illumination, thereby outperforming most reported catalysts. Experimental and theoretical data revealed that the dual vacancies promoted the production of reactive oxygen species (O2− and OH) and the adsorption of NO on the LDH. In situ spectroscopy demonstrated that NO was preferentially adsorbed at Lewis acidic sites, particularly exposed Fe3+ sites, converted into NO+, and subsequently oxidized to NO3− without the notable formation of the more toxic intermediate NO2, thereby alleviating risks associated with its production and emission.

012 facets modulated LDH composite for neurotoxicity risk assessment through direct electrochemical profiling of dopamine

Rising concerns of pesticide-induced neurotoxicity and neurodegenerative diseases like Parkinson's, Alzheimer's, and Multiple Sclerosis, are exacerbated by overexposure to contaminated waterbodies. Therefore, evaluating the risk accurately requires reliable monitoring of related biomarkers like dopamine (DA) through electrochemical detection. Layered double hydroxides (LDHs) have shown great potential in sensors. However, to meet the challenges of rapid detection of large patient cohorts in real-time biological media, they should be further tailored to display superior analytical readouts. Herein, a ternary LDH (Ni2CoMn0.5) was integrated with the sheets of thermally reduced graphene oxide (trGO), to expose more highly active edge planes of the LDH, as opposed to its generally observed inert basal planes. The improvement in detection performance through such a modulated structure-property is a prospect that hasn't been previously explored for any other LDH-based materials employed in sensing applications. The 2 folds superior electrochemical activity exhibited by the face-on oriented LDH with trGO as compared to the pristine LDH material was further employed for direct detection of DA in real blood plasma samples. Moreover, the designed sensor exhibited exceptional selectivity towards the detection of DA with a limit of detection of 34.6 nM for a wide dynamic range of 0.001–5 mM with exceptional stability retaining 88.56% of the initial current even after storage in ambient conditions for 30 days.

A comparison increasing the photodegradation power of a Ag/g–C3N4 /CoNi–LDH nanocomposite: Photocatalytic activity toward water treatment

For environmental applications, it is crucial to rationally design and synthesize photocatalysts with positive exciton splitting and interfacial charge transfer. Here, a novel Ag-bridged dual Z-scheme Ag/g-C3N4/CoNi-LDH plasmonic heterojunction was successfully synthesized using a simple method, with the goal of overcoming the common drawbacks of traditional photocatalysts such as weak photoresponsivity, rapid combination of photo-generated carriers, and unstable structure. These materials were characterized by XRD, FT–IR, SEM, TEM UV–Vis/DRS, and XPS to verify the structure and stability of the heterostructure. The pristine LDH, g-C3N4, and Ag/g-C3N4/CoNi-LDH composite were investigated as photocatalysts for water remediation, an environmentally motivated process. Specifically, the photocatalytic degradation of tetracycline was studied as a model reaction. The performance of the supports and composite catalyst were determined by evaluating both the degradation and adsorption phenomenon. The influence of several experimental parameters such as catalyst loading, pH, and tetracycline concentration were evaluated. The current study provides important data for water treatment and similar environmental protection applications.

Photocatalytic of anionic dyes on Congo red with M2+/Al (M2+=Ni, Mg, and Zn) layered double hydroxide intercalated polyoxometalate

The modification catalysts of layered double hydroxide (LDH) with polyoxometalate based on Keggin type were prepared and characterized using X-Ray, FTIR, and SEM to confirm the layered double hydroxide structure. Intercalation was successfully synthesized and showed a heterogeneous aggregate resulted from SEM analysis. The degradation parameters of LDH pristine and LDH composite were determined by observing a number of factors such as pH, catalyst weight, and degradation time. The modification material resulted by preparation material LDH and polyoxometalate (POM) successfully resulted in the lower band gap value compared to material pristine LDH allowing LDH polyoxometalate as photocatalysts to show good photocatalytic activities. The NiAl-SiW12O40 material had the highest percentage of degradation removing Congo Red up to 86% degradation when compared to another composite material, yet it was still significantly better than LDH pristine. The result showed that the LDH composite presented excellent photocatalytic activity in reducing Congo Red.

Optimization of parameters for adsorption of acid yellow 36 dye onto nitrate‐intercalated MgAl LDH nanoparticle using Box–Behnken design

AbstractBACKGROUNDLayered double hydroxide nanoparticles have been extensively investigated and exploited for the removal of harmful anions from contaminated water. For adsorption of acid yellow dye (AY) from contaminated water, nitrate‐intercalated MgAl layered double hydroxide (LDH) nanoparticles were synthesized using the co‐precipitation method with the refluxing condition in a nitrogen atmosphere.RESULTSThe X‐ray diffraction pattern of LDH nanoparticles showed that LDH nanopowder with nitrate in the interlayer position was successfully synthesized. The shift in (003) basal plane diffraction peak to a lower angle (2θ) of 7.75° in the LDH‐AY from 10.40° in the pristine LDH confirmed the intercalation of AY in the interlayer space of LDH. Variable factors for the adsorption of the AY on the LDH nanoparticles were examined in the batch process using ultraviolet–visible spectroscopy and those included the adsorbent dose (5–30 mg), the incubation time (3–60 min), the temperature (25–50 °C), the pH of the AY aqueous suspension (5–9) and the AY concentration (0.03–0.1 mg mL−1). Box–Behnken design was used to optimize the three independent variables of temperature, incubation time and pH of AY solution for the adsorption of the dye. The optimized values of the incubation time, temperature and pH were found to be 25.89 min, 35.99 °C and 5.16, respectively. A maximum adsorption rate of 0.00515 g mg−1 min−1 of AY onto LDH nanoparticles was found at a solution pH of 5 and a temperature of 50 °C. The adsorption kinetics of the AY at different suspension pH values and temperature followed a pseudo‐second‐order kinetic model. Furthermore, an adsorption isotherm study for the adsorption of AY at a temperature of 40 °C and pH 5 followed a Langmuir isotherm model, and the maximum adsorption capacity of the AY was calculated to be 412.55 mg g−1 with excellent regeneration capacity.CONCLUSIONThe study revealed that the synthesized nitrate intercalated Mg Al LDH nanoparticles using the reflux conditions offered promising potential to adsorb acid yellow 36 dye form its aqueous solution. © 2023 Society of Chemical Industry (SCI).

Synthesis and characterization of quercetin-layer double hydroxide (LDH) nanohybrid and their enhanced antioxidant activity

ABSTRACT. This research included the synthesis of pristine nitrate-type Zn2Al-LDH by means of Co-precipitation, which was then followed by hydrothermal treatment. Ion exchange is used to stabilize the produced pristine LDH nano layer, which is used for the encapsulation of bioactive molecules. Quercetin, which has an antioxidant function, is used. XRD was used to investigate the newly synthesized quercetin-LDH (QC-LDH) compound. Quercetin was discovered to be entirely deprotonated as a result of XRD research, and it was also shown to be stabilized in between LDH lattices as a result of electrostatic contact. On the basis of the diphenyl picrylhydrazyl (DPPH) method, the anti-oxidant property was discussed, and it was discovered that the quercetin that was free from the LDH layer helped as an owing antioxidant to scavenge DPPH radicals in ethanol solvent at concentrations ranging from 80-100%, depending on the concentration level. The powder X-ray diffraction patterns indicate that the incorporation of quercetin into the interlayer led to an expansion of the interlayer arrangement to 0.88 and 1.46 nm, respectively. According to the findings of a variety of characterization techniques, the QC-LDH may be regarded as a good antioxidant material with potential drug delivery system.
 
 KEY WORDS: Layer double hydroxide, Antioxidant activity, Quercetin, Biocompatibility
 
 Bull. Chem. Soc. Ethiop. 2023, 37(4), 917-929.
 DOI: https://dx.doi.org/10.4314/bcse.v37i4.9

Sonochemical synthesis, characterization and investigation of the electrochemical hydrogen storage properties of Ho3Fe5O12/Mg2Al(OH)7 nanocomposites

It has been noted that hydrogen has attracted extensive consideration in the field of new energy, resulting in a wide range of studies concerning hydrogen production, storage, and use. As part of this research, mixed metal oxide materials with double layer hydroxides are primarily studied for their hydrogen storage capacity. In terms of hydrogen storage capacity, the sonochemically synthesized Ho3Fe5O12/Mg2Al(OH)7 nanocomposites (HF/MgAl(OH)) with different ratios of Ho3Fe5O12 to Mg2Al(OH)7 were compared with pristine LDH of Mg2Al(OH)7. It has been demonstrated that the capacity of Ho3Fe5O12/Mg2Al(OH)7 nanocomposites (422 mAhg−1) with a 1:1 ratio of Ho3Fe5O12 to Mg2Al(OH)7 is significantly higher than pristine LDH (213 mAhg−1).