Layered Double Hydroxide Matrix Research Articles

Layered double hydroxides matrix as host for curcumin loading: structural and spectroscopic investigations

Layered double hydroxides matrix as host for curcumin loading: structural and spectroscopic investigations

Intercalated Organic Redox-active Anions for Enhanced Capacity of Layered Double Hydroxides

A Layered Double Hydroxide (LDH) compound LDH ([Mg2Al(OH)6]+ x 2 H2O) intercalated with a redox active organic anion, Anthraquinone-2-sulfonate (AQS), has been envisioned as an electrode material for high power aqueous based battery. The purpose is to use this interlayer redox active molecule for the enhancement of the specific capacity at the LDH composite electrode, which should allow fast charge transfer at the negative electrode for high power storage applications. This is achieved by the reduction of AQS in charge and oxidation in discharge within a redox inactive LDH matrix. The first charge of this new material [Mg2Al(OH)6]+[AQSO3]− x 2 H2O leads to a capacity of 100 mAh g−1 at − 0.78 V vs Ag/AgCl (based on the weight of the active material) when operated in aqueous 1 M sodium acetate electrolyte. However, low cycling stability was observed, since a drastic loss in specific capacity occurs after the first charge. This study focuses at elucidating the mechanism behind this phenomenon via in situ UV/vis experiments. Subsequently, the dissolution of charged AQS anions into the electrolyte during the first charge of the anode has been identified and quantified. Such understanding of fading mechanism might lead to the design of improved LDH-based electrodes, which utilize redox active anions working in the positive potential range with enhanced cycling ability.

N-doped carbon materials produced by CVD with the compounds derived from LDHs

Layered double hydroxides (LDHs) of various compositions, i.e. Mg–Al, Mg–Mn–Al, are applied as the precursors of metal oxides for the preparation of N-doped carbon materials via chemical vapour deposition (CVD) with acetonitrile (as carbon and nitrogen source) at 600 and 700 °C. The use of Mn-containing LDHs for the preparation of the carbon materials is a novelty. The impact of transition metal species, i.e. MnxOy, in a blend of metal oxides derived from LDHs on the amount of carbon deposit and its composition, morphology, textural and capacitive properties is investigated. Mn-containing species occurring in a mixture of metal oxides enhance the quantity of carbonaceous product compared to those derived from Mg–Al LDHs. Thermally heated Mg–Mn–Al LDHs contain structural defects due to manganese oxides, which promote the formation of carbon deposit, especially higher production of amorphous carbons. The addition of Mn into Mg–Al LDHs matrix leads to carbon particles with increased N-doping and enhanced volume of mesopores. Furthermore, graphitic domains occurring in the carbon materials obtained with Mg–Mn–Al LDHs are thicker than those in the corresponding samples obtained with Mg–Al LDHs as Mn-containing species influence the concentration and location of N-containing groups in graphitic array. The specific capacitance of the carbon materials produced by CVD with the compounds derived from Mg–Al LDHs or Mg–Mn–Al LDHs is comparable (20–25 μF cm−2). The formation of electrical double layer at electrode/electrolyte interface is easier for the carbon materials prepared at 700 °C than for the carbon materials prepared at 600 °C. The maximum charge is stored either in the shallow parts of carbon particles for the former, as they contain bottleneck mesopores, or in the deep parts of carbon particles for the latter, as they contain slit-shaped mesopores.Graphical abstract

Highly active atomic Cu catalyst anchored on superlattice CoFe layered double hydroxide for efficient oxygen evolution electrocatalysis

Developing active, natural abundant and non-expensive electrocatalysts for large scale production and storage of clean hydrogen (H 2 ) fuel is a prerequisite to drive stable water splitting reaction. Herein, atomic Cu species loaded on hierarchical flower-like CoFe layered double hydroxides (LDHs) superlattice (denoted as Cu x /CoFe LDHs) were firstly fabricated by a facile co-precipitation method followed by a room temperature treatment to load the atomic Cu species from alkaline copper salt solution. The superlattice structure was proved by the high resolution transmission electron microscopy (HRTEM). Remarkably, benefiting from high level long ordering associated with vacant cation sites and defects, the unique superlattice structural features and the atomic Cu % loading onto the LDHs matrix, the obtained Cu x /CoFe LDHs electrocatalyst exhibited superior activity and stability for oxygen evolution reaction (OER). The loaded atomic Cu species improves the electronic structure and provides more exposed active sites due to synergetic electron coupling between Copper and the LDHs. These atomic species have outstanding potentials for achieving high selectivity and reactivity in electrocatalysis and heterocatalysis. Importantly, the efficient resulted Cu 4.76 /CoFe LDHs electrode in which the atomic Cu % loading ratio is 4.76% showed the best electrocatalytic activity which only required the much lower overpotential of 253 mV to reach 10 mA/cm 2 and a small Tafel slope of 63 mV/decade in 1 M KOH. This electrocatalyst possessed unique superior features to many other state-of-the-art earth-abundant electrocatalysts. This work paves a facile and novel method for enhancing the catalytic activity of CoFe LDHs based electrocatalyst, which may be extended to the synthesis of future electrocatalysts having highly active OER performance. • Novel synthesis of Cu x /CoFe LDHs electrocatalysts via co-precipitation followed by atomic Cu species loading. • 3D hierarchical porous flower-like morphologies offering more accessible channels and active sites. • Electrons transfer from M (Co or Fe) to Cu via M–O–Cu bonds. • The Cu 4.76 /CoFe LDHs electrode showed much lower overpotential and small Tafel slope. • The loaded atomic Cu species improves the electronic structure and provides more exposed active sites.

Mass Spectrometry Imaging of Low-Molecular-Weight Phenols Liberated from Plastics.

The abundant and heterogeneous distribution of toxic phenol from plastics has drawn worldwide attention. However, the common analysis methods failed to identify the accurate species of these phenolic hazards from plastics in a direct and nondestructive approach. Herein, we demonstrate the layered double hydroxides (LDHs) as a novel matrix in matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) for low-molecular-weight phenols leaked from plastics. LDHs own abundant hydroxyl groups to facilitate chemoselectivity and ionization of phenols through the formation of hydrogen bonds with these phenols. More importantly, the LDH matrix could provide a distinguishable signal for the homolog and isomeride of these phenolic hazards. The developed method could realize nondestructive and in situ mapping of phenolic hazards in plastics. Our success could help to track the low-molecular-weight compounds liberated from plastics and supply spatial information for polluted plastics. We anticipated that the proposed approach could provide sufficient information to evaluate and alarm the safety of food packaging plastics.

Synthesis and evaluation of layered double hydroxide based sorbent for hot gas cleanup of hydrogen chloride

In this study, we report on the synthesis and evaluation of a sodium, magnesium, and aluminum (Na-Mg-Al) layered double hydroxide (LDH) based sorbent for hydrogen chloride (HCl) removal at concentrations found in lignocellulosic biomass derived syngas. The LDH was synthesized by a spontaneous self-assembly method and further calcined at 700 °C to produce a mixed metal oxide sorbent that we evaluated in the hot gas cleanup of hydrogen chloride at 100 parts per million. The performance of this sorbent was evaluated in a fixed bed reactor from 400 to 600 °C against that of a commercial magnesium and aluminum LDH (ComLDH) material that does not contain sodium in the matrix as well as two other commercial sorbents, sodium carbonate (Na2CO3) and sodium aluminate (NaAlO2).Our Na-Mg-Al LDH is thermally stable in the hot gas cleanup temperature range. During fixed bed experiments, our calcined LDH mixed metal oxide was effective in reducing hydrogen chloride’s concentration below the breakthrough concentration of 1 ppm from 400 to 600 °C for more than 14 h. The better performance of our calcined LDH compared to calcined commercial LDH supported our hypothesis that sodium incorporation in the LDH matrix enhances HCl sorption. Based on comparison against the commercial Na-based sorbents, the following rankings by temperature observed: LDH > NaAlO2 > Na2CO3 at 400 °C; LDH = NaAlO2 > Na2CO3 at 500 °C; and Na2CO3 = NaAlO2 = LDH at 600 °C.

Synthesis and fine spectroscopy tuning of the hyperspectral simulation material based on organic anions intercalated Mg-Al layered double hydroxide

Organic anions have been intercalated into the interlayer of Mg-Al layered double hydroxides (LDHs) via a hydrothermal method to tune the visible and near-infrared reflection spectrum of hybrid pigments based on LDHs. The prepared samples were analyzed by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetric-differential scanning calorimetry, visible and near-infrared spectrophotometry, and CIE 1976 L*a*b* color scales. The effects of the intercalated organic anions on the structure, morphology, color, and spectral characteristics of Mg-Al LDH materials were systematically investigated. The results show that the colored anions of acid green (AG) and acid yellow (AY) have been successfully intercalated into the interlayer space of LDHs through the anion displacement process. The visible light reflection spectrum of LDH matrix can be easily tuned by adjusting the intercalated concentration of anions and the relative ratio of AG and AY, which leads to the color of prepared samples changing from the original white into blue, yellow, green, and dark black. Combined with the color adjusting ability of organic anions and the high hydroxyl property of LDH substrate, the typical visible and near-infrared spectral characteristics of natural green plants can be accurately simulated. The correlation coefficient of spectrum shape between the prepared pigment and green plant in the whole range of 400–2500 nm is as high as 0.94. Moreover, the thermal stability of LDH materials is improved by the intercalated organic anions, whose spectral properties can withstand high temperatures of at least 250 °C. The hybrid materials could be used as a functional pigment to prepare green camouflage coatings, showing their potential application in the field of hyperspectral camouflage.

Restriction‐Induced Luminescence Enhancement in 2D Interlayer Supramolecular Infinite Solid Solution for Cell Imaging

AbstractConsidering the anionic intercalation capacities of layered double hydroxides (LDH), 2‐hydroxy‐4‐methoxybenzophenone‐5‐sulfonate (BP4) and decanesulfonate (DES) anions are cointercalated into the interlayers of Mg2Al‐LDH to form DES–BP4 (x%)/LDH composites, which can be regarded as 2D interlayer supramolecular infinite solid solutions (2D ISISSs), according to a structural analysis. Compared to those of pristine BP4, the fluorescence properties of DES–BP4 (x%)/LDH 2D ISISSs are significantly improved and their emission peak wavelengths are adjustable in the range of 491–510 nm by varying x. DES–BP4 (8%)/LDH exhibits the optimal fluorescence properties. Its quantum yield, lifetime, and fluorescence intensity are increased ≈14, 4, and 45 times, respectively. Moreover, its nonradiative relaxation rate constant is decreased five times, while its radiative relaxation rate constant is increased three times. The luminescence enhancement can be attributed to the formation of the 2D ISISSs system, which effectively restricted the intramolecular movements of BP4 anions. Owing to its enhanced fluorescence properties, DES–BP4 (8%)/LDH exhibits outstanding performances for cell penetration and confocal fluorescence imaging and lifetime imaging of lysosome in HeLa cells. Therefore, the 2D ISISSs based on the LDH matrix provide a novel route to optimize the performances of functional molecules and expand their applications.

Chlorpromazine Electro‐oxidation at BDD Electrode Modified with nZVI Nanoparticles Impregnated NiAl LDH

AbstractNanocomposite of nanoscale zero‐valent iron (nZVI) and layered double hydroxide (LDH) was used as modifier for boron‐doped diamond electrode in determination of anti‐psychotic drug chlorpromazine (CPZ). nZVI nanoparticles were prepared by liquid phase reduction of ferric chloride with sodium borohydride on the surface of NiAl LDH matrix owing to the strong exchange and confinement efficiency of LDH. The structure, binding and surface properties of the nZVI@LDH nanocomposite were monitored using powder X‐ray diffractometry, FT‐IR spectroscopy, scanning and transmission microscopy and BET techniques. The electrochemical properties of the modified electrode were investigated by CV and EIS, performed in a phosphate buffer containing ferro/ferricyanide as redox probe. The modified electrode exhibited excellent electrochemical performance compared with unmodified electrode. As regard potential application of the nanocomposite surface to the CPZ detection, square‐wave voltammetric signals showed a good linear correlation over CPZ concentrations in a broad range from 0.1 to 8.0 μM with low detection limit of 0.005 μM. Nevertheless, these results suggest that the proposed nanocomposite modifier surface provides exceptional synergy and significant enhancement effect to the voltammetric response of CPZ and thus could be applied as highly efficient and stable platform of sensors in clinical analysis.

Synthesis of ionic liquid intercalated layered double hydroxides of magnesium and aluminum: A greener catalyst of Knoevenagel condensation

Due to their structural merits that arise from their stability and high surface area, the layered double hydroxide (LDH) materials have caused strong attention. These characteristics provided intriguing possibilities with improved efficiency for catalytic applications. In this work, the preparation of 1-butyl-3-methylimidazolium hydroxide ([BMIM]+OH−) intercalated by a facile approach in a layered double hydroxide (LDH) matrix is reported and its implementation as a greener catalyst is shown. Different physico-chemical techniques such as XRD, FTIR, TGA, and N2-physisorption, HRTEM, and CO2 adsorption are implemented to characterize the structure of the fabricated catalysts. The [BMIM]+OH−/LDH exhibit outstanding catalytic performance in Knoevenagel condensation, resulting from the high LDH surface area and synergistic effects between both the intercalated ionic liquid and LDHs matrix. Knoevenagel’s fabricated catalysts can be exploited to catalyze different condensations and can be reused well. This work therefore generates good opportunities in the field of catalysis for the preparing and implementation of LDH-based catalysts.

Abiotic humification of phenolic pollutant to form a hybrid adsorbent for toxic metals by LDH based composite

As a novel method for recycling phenolic compound from wastewater, a hybrid adsorbent has been synthesized through chemical catalytic humification. The results show that the heterogeneous catalyst for humification contains a lamellar Zn2Al-NO3 layered double hydroxide (LDH) matrix in which nanostructural Fe3O4 is embedded. Based on this catalyst, the catechol, a typical phenolic compound can be effectively transformed into humic-like substance (HLS) and almost all of them are in-situ attached on the LDH matrix to form a hybrid adsorbent. The conversion ratio of humification can reach up to 65% and loading amount of HLS can reach around 668 mg/g solid. Both the substrate concentration and pH have little effect on the properties of HLS whose molecule weight are around 1000 g/mol and total contents of carboxyl and phenolic hydroxyl are approximately 8.5 mmol/g. The hybrid adsorbent whose surface and part of interlayer are both loaded with HLS presents a good performance on adsorption of toxic metals. The adsorption isotherms of Pb2+, Cu2+, Ni2+ and Cd2+ fit with monolayer adsorption models and the adsorption capacity can reach up to 1.34, 1.31, 0.98 and 0.50 mmol/g respectively with an adsorption preference order of Pb2+ > Cu2+ > Ni2+ > Cd2+.

Synthesis of NiAl- layered double hydroxide with nitrate intercalation: Application in cyanide removal from steel industry effluent.

Cyanide contamination in steel plant wastewater is a challenge. Nitrate intercalated nickel aluminum layered double hydroxide (LDH) is specially designed and synthesized for adsorption of cyanide from wastewater. The LDH was characterized by Field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and BET surface analyzer. Formation of nanosized plate like LDH particles was confirmed by FESEM analysis. FTIR analysis confirmed the intercalation of nitrate ions in the interlayer space of nickel-aluminum layered double hydroxide. Adsorption of cyanide in the LDH matrix was identified by FTIR study. Ion exchange was the prevalent mechanism of cyanide adsorption. The specific surface area of LDH was 142 m2/g with average pore size of 1.9 nm. The spent LDH could be regenerated using a chemical method and was reused up to five cycles. The efficiency of the LDH was evaluated using real life cyanide containing wastewater from steel plant.

Modulated transition metal-oxygen covalency in the octahedral sites of CoFe layered double hydroxides with vanadium doping leading to highly efficient electrocatalysts.

The development of efficient and stable non-noble-metal electrocatalytic materials for the oxygen evolution reaction (OER) is a huge and important challenge at present. Herein, we report the prominent enhancement of OER activity via doping vanadium into CoFe-based layered double hydroxide (LDH) electrocatalysts. Electrochemical characterization shows that the Co2Fe0.5V0.5 LDH grown on carbon papers (CPs) has an enormous electrochemical surface area (ECSA) and exhibits the smallest overpotential of 242 mV at 10 mA cm-2, which only requires a small Tafel slope of 41.4 mV dec-1 in 1 M KOH solution. The X-ray photoelectron spectroscopy (XPS) peak position of Co, Fe and O moves slightly to higher binding energy, elucidating the improved covalency of the metal-oxygen bond after V doping. DFT+U simulation indicates that the outstanding electrocatalytic activity of Co2Fe0.5V0.5 could be ascribed to the increased metal-oxygen covalency in LDH after V element doping, and facilitates the charge-transfer from oxygen to the metal. This finely tuned strategy by V doping into the CoFe-based LDH matrix can adjust the covalency of metal-oxygen bridges and enhance its electrocatalytic activity for the OER. In this work, we also present a general method to study various highly efficient metal hydroxide catalysts for the OER.

Confined Synthesis of Carbon Nitride in a Layered Host Matrix with Unprecedented Solid-State Quantum Yield and Stability.

Fluorescent carbon nanomaterials have drawn tremendous attention for their intriguing optical performances, but their employment in solid-state luminescent devices is rather limited as a result of aggregation-induced photoluminescence quenching. Herein, ultrathin carbon nitride (CN) is synthesized within the 2D confined region of layered double hydroxide (LDH) via triggering the interlayer condensation reaction of citric acid and urea. The resulting CN/LDH phosphor emits strong cyan light under UV-light irradiation with an absolute solid-state quantum yield (SSQY) of 95.9 ± 2.2%, which is, to the best of our knowledge, the highest value of carbon-based fluorescent materials ever reported. Furthermore, it exhibits a strong luminescence stability toward temperature, environmental pH, and photocorrosion. Both experimental studies and theoretical calculations reveal that the host-guest interactions between the rigid LDH matrix and interlayer carbon nitride give the predominant contribution to the unprecedented SSQY and stability. In addition, prospective applications of the CN/LDH material are demonstrated in both white light-emitting diodes and upconversion fluorescence imaging of cancer cells.

Fulvic acid anchored layered double hydroxides: A multifunctional composite adsorbent for the removal of anionic dye and toxic metal

A novel multifunctional composite adsorbent which possesses the ability for anion exchange and toxic metal complexation has been synthesized by the hybridization of layered double hydroxides (LDH) and fulvic acid (FA) in this study. The results show that FA with lots of functional groups can be effectively and stably anchored on the surface of LDH through coagulation process without occupying the interlayer of LDH. Therefore, the anion exchange ability remains and the adsorption capacity of Orange II can reach 1.9mmol/g, which is almost as much as stoichiometric anion exchange capacity of pure LDH. Moreover, the composite adsorbent’s adsorption capacity of Cu2+, Pb2+, Ni2+ and Cd2+ can also get to 2.25mmol/g, 0.98mmol/g, 0.99mmol/g and 0.16mmol/g respectively with an adsorption preference order of Cu2+>Pb2+>Ni2+>Cd2+. In addition, Orange II and toxic metals are able to be simultaneously removed by this composite adsorbent, and the adsorption of toxic metals can be enhanced by the synergetic adsorption of Orange II. Anion exchange with Cl− in LDH matrix accounts for the adsorption of Orange II, while the adsorption of toxic metal is mainly attributed to the complexation of carboxyl functional group derived from FA.

In-situ growth of ZIF-8 on layered double hydroxide: Effect of Zn/Al molar ratios on their structural, morphological and adsorption properties

In-situ growth of Zeolite imidazolate frameworks (ZIFs) on layered double hydroxides (LDHs) to form porous composites is a promising and challenging strategy to develop materials for separation application. Herein, the Zn-Al LDH with different Zn/Al molar ratios was prepared and used as matrix for the growth of ZIF-8 on its surface. The resulting composites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N2 physisorption, thermogravimetric (TG), scanning electron microscope (SEM) and elemental analysis followed by testing for AsV removal from aqueous solution. Results showed that ZIF-8 could form on the surface of LDH with different Zn/Al molar ratios. At low Zn/Al molar ratios, the morphology and surface area of the ZIF/LDH composites and the content of ZIF-8 in the composites were little affected by the Zn/Al molar ratio. With increasing Zn/Al molar ratio, ZIF-8/LDH exhibited a lower surface area, which resulted from reduced content of ZIF-8 caused by impurities generated in the LDH matrix. All ZIF-8/LDH samples showed high AsV adsorption capacity, which was significantly higher than that of pure LDH or ZIF-8.

Thermal behavior of LDH 2CuAl.CO3 and 2CuAl.CO3/Pd

Cu/Al layered double hydroxide (LDH) can be used as a catalyst for important processes such as cross-coupling reactions. This property may be improved by adding palladium by either impregnation or intercalation. Therefore, the LDH matrix and its composites with Pd0 or [PdCl4]2− have been prepared. By powder X-ray diffraction, FT-infrared spectroscopy, thermogravimetric and elemental analysis it was determined the LDH formula Cu4Al2(OH)12CO3.4H2O, with malachite as the second phase. The LDH thermal decomposition occurs between 120 and 600 °C, having as intermediates the double oxi-hydroxide and the mixed oxide phases. At 800 °C the residue is composed of CuO and CuAl2O4. The composites were obtained employing [PdCl4]2− and Pd2(dba)3 as precursors, and the solvent choice for this process was shown to be of significant importance: the materials obtained using DMF had Pd impregnated in the surface, while the usage of water promoted the intercalation of [PdCl4]2− in the LDH matrix. The thermogravimetric analysis was able to distinguish the mode of supporting palladium between the composites being a reliable characterization for such task.

Theoretical and experimental study on the topotactic transformation mechanism of Zn-Al layered double hydroxides

Layered double hydroxides (LDHs) are a class of minerals with nanoscale two-dimensional layered structure. The topotactic transformation of LDHs under calcination and the reconstruction behavior (memory effect) of the calcined LDHs in aqueous solution play a key role in the fabrication of high dispersed metal nanocatalysts. The thermal topotactic transformation mechanism of ZnAl-layered double hydroxides (LDHs) and memory effect of LDHs were investigated by density functional theory based molecular dynamics (MD) simulation, combined with thermogravimetric/differential thermal analysis (TG-DTA). TG-DTA results reveal that the LDH phase undergoes two key endothermic events at 273 and 800 °C. The results show that the anion in LDHs decomposes to CO2 and H2O via a monodentate intermediate at 273 °C, and H2O releases prior to CO2. After the decomposition of interlayer CO32− at 273 °C, the distribution of metal cations in LDH matrix changed heavily along both LDH(001) facet and the c -axis direction perpendicular to the (001) facet. The dehydrated products cannot reconstruct back to the hydroxide phase, showing no memory effect. At 800 °C, a complete collapse of layered structure occurs, resulting in a totally disordered cation distribution and plenty of holes in the final product. This work will be helpful for the design and preparation of highly dispersed nanocatalysts derived from LDHs precursors.

Assembly of LDHs-based fluorescent materials and investigations on their two-dimensional confinement effect

Layered double hydroxides (LDHs) are a family of inorganic host materials which have been widely used in fluorescence display, imaging and sensor, due to their specific layered structure and two-dimensional confined interlayer space. In this review, we summarized the recent progress in the fluorescent guests, assembly methods of layered structure and host-guest interactions. Furthermore, the influences of 2D confinement effects of LDHs matrix (geometry confinement and electron confinement) on the fluorescence property of guests are discussed.

Design and synthesis of ternary-component layered double hydroxides for high-performance supercapacitors: understanding the role of trivalent metal ions

To understand the insightful mechanics of the effects of the trivalent metal ions on the electrochemical performance of ternary-component layered double hydroxides (LDH), the ternary LDH composed by NiCoAl-LDH, NiCoAl0.5Fe0.5-LDH and NiCoFe-LDH are designed, synthesized and characterized. Despite bivalent metal ions (Ni2+, Co2+) having been demonstrated to play a highly specialized role in surface redox chemistry, the role of the trivalent metal ions within the metal hydroxide layer has not been elucidated yet in supercapacitor applications. Here we demonstrated that Al3+ has a positive effect on the stabilization of host layers of LDH, which leads to the improvement of the electrochemical performance. It was also found that Al3+ could regulate the crystallinity, hydrophilicity and nanosheets stacking of LDH. Further, comparative studies show that NiCoAl-LDH exhibited superior specific capacitance of 1153Fg−1 at 6Ag−1, and excellent cycling stability (ca. 92.97% capacitance retention after 3000 cycles). We attribute such remarkable enhancement in cyclic performance to the framework stability of Al3+ in the multi-metal LDH matrix layer. These results highlight the importance of trivalent metal ions in ternary-component LDH for high-performance supercapacitors and may guide future design and synthesis of LDH.