Hierarchical Layered Structure Research Articles

Fabrication of hierarchical layered structure in Zr/Ti composite via multi-step heat treatments and its effect on the mechanical properties

The strength and ductility of metallic structural materials are two pivotal properties generally considered mutually contradictory. In the past few decades, numerous heterogeneous materials have been designed and fabricated to overcome this trade-off. Biomimetic-designed hierarchical layered (HL) materials represent a promising approach. In the present study, HL Zr/Ti materials with three hierarchical levels were fabricated via multi-step heat treatments. Scanning Electron Microscopy (SEM), Transmission electron microscope (TEM), Electron Backscatter Diffraction (EBSD), Transmission Kikuchi Diffraction (TKD), and Energy Dispersive X-ray Spectroscopy (EDS) were employed to observe the evolution of the HL microstructure. The mechanical properties of the HL Zr/Ti materials were assessed through hardness and tensile tests, analyzing the influence of microstructural changes in the diffusion layer on the overall mechanical performance. Our results demonstrated that the HL structure could introduce extra strength beyond the rule of mixtures (ROM) due to multiple-scaled hetero-deformation induced (HDI) strengthening. Additionally, the refinement of the second-level layer thickness effectively inhibited crack propagation. This research provides new insights into developing multi-level HL materials with enhanced mechanical properties through cost-effective and scalable manufacturing processes.

Conversion of secondary aluminum dross into hierarchical carbonate-intercalated Mg-Al layered double hydroxide for efficient CO2 capture

This paper explores the preparation of hierarchical Mg-Al layered double hydroxide (LDH) from secondary aluminum dross waste for the first time. The aluminum content of the waste was initially extracted in the form of a sodium aluminate solution using a multistep wet chemical process. CO3-intercalated Mg-Al LDH was then prepared at pH values of 9 and 11 by adding magnesium chloride to a mixed solution of sodium aluminate and sodium carbonate. The X-ray diffraction (XRD) analysis revealed that a pure LDH structure could be formed at pH 11. The quantification of the XRD data revealed that the synthesized LDH had an interlayer spacing of 3.1 Å. The microstructural porosity was 0.76 cm3/g, and the specific surface area was 134 m2/g. The field emission scanning electron microscopy (FESEM) analysis revealed a hierarchical layered structure composed of flake-like particles in the microstructure. The elemental mapping of the synthesized LDH showed a proper distribution of Mg, Al, C, and O. The synthesized Mg-Al-CO3 LDH was then used for a study on CO2 capture. The CO2 capture experiments demonstrated that the amount of CO2 adsorption is influenced by temperature, gas pressure, adsorbent mass, and exposure duration. Investigating the effects of time and temperature revealed that a CO2 adsorption of 0.94 mmol/g can be achieved at a temperature of 25 °C during a 90-minute exposure period. Varying the gas pressure from 1 to 2.5 bar, while maintaining a constant temperature of 25 °C and an adsorbent mass of 1.5 g, resulted in an increase in CO2 adsorption from 1.7 to 2.3 mmol/g. Reusability tests showed that the LDH could maintain a satisfactory adsorption value of 0.84 mmol/g after 5 cycles, indicating its potential for repeated use.

Degradation of trichloroacetic acid by Fe/Ni bimetallic reactive PMS with hierarchical layered structure

Overuse of chlorinated disinfectants leads to a significant accumulation of disinfection by-products. Trichloroacetic acid (TCA) is a typical carcinogenic disinfection by-product. The efficacy of the conventional degradation process is reduced by the complex nature of its structure, causing a yearly increase in its prevalence within the ecological environment and consequent infliction of significant harm. In this paper, TCA was chosen as the research subject, Fe/Ni bimetallic nanoparticles were employed as the reducing catalyst, ZIF-8@HMON as the catalytic carrier combined with Fe/Ni nanoparticles, and peroxymonosulfate (PMS) was introduced to construct the reducing-advanced oxidation synergistic system and investigated the effect of this system on the degradation performance and degradation pathway of TCA. Various characterization techniques, including TEM, SEM, XRD, FT-IR, XPS, BET, were employed to investigate the morphology, element composition and structure of composite materials analysis. Moreover, the conditions for TCA degradation can be optimized by changing the experimental environment. The results showed that 25 mg of composite catalyst (mole ratio Fe: Ni = 1:1) and 10 mg of PMS effectively degraded TCA within 20–80 mg/L range at pH = 3 and 55 °C, achieving maximum degradation within 20 min. Finally, the potential pathways of TCA degradation were analyzed using EPR and LC-MS, and the corresponding reaction mechanisms were proposed.

Ultrafast Bi-Directional Bending Moisture-Responsive Soft Actuators through Superfine Silk Rod Modified Bio-Mimicking Hierarchical Layered Structure.

Development of stimulus-responsive materials is crucial for novel soft actuators. Among these actuators, the moisture-responsive actuators are known for their accessibility, eco-friendliness, and robust regenerative attributes. A major challenge of moisture-responsive soft actuators (MRSAs) is achieving significant bending curvature within short response times. Many plants naturally perform large deformation through a layered hierarchical structure in response to moisture stimuli. Drawing inspiration from the bionic structure of Delosperma nakurense (D. nakurense) seed capsule, here the fabrication of an ultrafast bi-directional bending MRSAs is reported. Combining a superfine silk fibroin rod (SFR) modified graphene oxide (GO) moisture-responsive layer with a moisture-inert layer ofreduced graphene oxide (RGO), this actuator demonstrated large bi-directional bending deformation (-4.06±0.09 to 10.44±0.00cm-1) and ultrafast bending rates (7.06cm-1s-1). The high deformation rate is achieved by incorporating the SFR into the moisture-responsive layers, facilitating rapid water transmission within the interlayer structure. The complex yet predictable deformations of this actuator are demonstrated that can be utilized in smart switch, robotic arms, and walking device. The proposed SFR modification method is simple and versatile, enhancing the functionality of hierarchical layered actuators. It holds the potential to advance intelligent soft robots for application in confined environments.

A note about why deep learning is deep: A discontinuous approximation perspective

AbstractDeep learning has achieved unprecedented success in recent years. This approach essentially uses the composition of nonlinear functions to model the complex relationship between input features and output labels. However, a comprehensive theoretical understanding of why the hierarchical layered structure can exhibit superior expressive power is still lacking. In this paper, we provide an explanation for this phenomenon by measuring the approximation efficiency of neural networks with respect to discontinuous target functions. We focus on deep neural networks with rectified linear unit (ReLU) activation functions. We find that to achieve the same degree of approximation accuracy, the number of neurons required by a single‐hidden‐layer (SHL) network is exponentially greater than that required by a multi‐hidden‐layer (MHL) network. In practice, discontinuous points tend to contain highly valuable information (i.e., edges in image classification). We argue that this may be a very important reason accounting for the impressive performance of deep neural networks. We validate our theory in extensive experiments.

Bioinspired sustainable cellulose-based nanocomposites with remarkable flame-retardant performance

Inspired by the hierarchical layered structure of nacre, bioinspired nanocomposites with unique flame-retardant and mechanical properties were fabricated from phytic acid-modified CNF and GO.

Enhancing Cd(II) and U(VI) remediation through synergistic utilization of GCN-supported MgFe-layered double hydroxide

Due to the significant concentration of heavy metals in the contaminated area, it presents an imminent threat to both living organisms and the environment. In this research, we concentrate on finding an effective solution for eliminating Cd(II) and U(VI) from water. Our approach involves utilizing MgFe-layered double hydroxide (LDH) nanosheets combined with graphitic carbon nitride (GCN) nanosheets to ensure the effective elimination of these hazardous metal ions. The characterization techniques, including SEM, XPS, XRD, and BET analysis, confirmed the hierarchical layered structure of GCN/MgFe LDH with a significant surface area of 127.91 m2/g. Batch investigations demonstrated that the pH of the solution influences the elimination of both metal ions, while kinetics and equilibrium data well align with a pseudo-second-order model and the Langmuir model (R2 = 0.996–1.0), respectively. GCN/MgFe LDH demonstrated impressive removal capacities of 312.30 mg/g and 273.42 mg/g for Cd(II) and U(VI) respectively. A thermodynamic analysis indicated that the adsorption process of both metal ions was endothermic and spontaneous. Furthermore, the GCN/MgFe LDH can be reused for over five cycles. In the fourth cycle, it maintained a removal percentage of over 95 % for both metal ions when 0.1 M HNO3 was used for desorption. In continuous column tests, the GCN/MgFe LDH reduced metal ion concentrations to levels below USEPA standards (<0.005 mg/L and 0.003 mg/L for Cd(II) and U(VI), respectively) for up to 4000 bed volumes, demonstrating its potential for wastewater treatment.

Benefiting from the multiple effects of ferrocene and cyclotriphosphazene bi-based hierarchical layered nanosheets towards improving fire safety and mechanical properties of epoxy resin

Epoxy resin (EP) is widely used in automobiles, aerospace, electrical and electronic fields. However, the overloading of flame retardant will heavily deteriorate the mechanical properties of EP. In this paper, flame retardant nanosheets (FH) with hierarchical layered structure was self-assembled by combining ferrocene formaldehyde (Fc-CHO) and hexa-aminophenoxy-cyclotriphosphazene (HACP) through a nucleophilic reaction. The limiting oxygen index (LOI) of the EP/FH2 nanocomposite with a 2 wt% loading of FH increased to 31.3% and the UL-94 V-0 rating was achieved due to the multiple synergistic flame retardant effects between ferrocene and cyclotriphosphazene, as well as the barrier performance of the FH nanosheets. Simultaneously, in the cone calorimeter (CC) test, the peak heat release rate (pHRR) and total smoke production (TSP) were reduced by 30.2% and 19.0% compared with EP, respectively. What's more, toughness of the EP/FH2 nanocomposite were greatly improved owing to the low loading and good compatibility of FH nanosheets in EP. In short, this work provides valuable insights into the design of flame retardant nanosheets and targets to balance the flame retardancy and mechanical properties of EP with low addition amounts.

Ballistic Behavior of Bioinspired Nacre-like Composites.

In this paper, the ballistic performance of a multilayered composite inspired by the structural characteristics of nacre is numerically investigated using finite element (FE) simulations. Nacre is a natural composite material found in the shells of some marine mollusks, which has remarkable toughness due to its hierarchical layered structure. The bioinspired nacre-like composites investigated here were made of five wavy aluminum alloy 7075-T651 (AA7075) layers composed of ~1.1-mm thick square tablets bonded together with toughened epoxy resin. Two composite configurations with continuous layers (either wavy or flat) were also studied. The ballistic performance of the composite plates was compared to that of a bulk monolithic AA7075 plate. The ballistic impact was simulated in the 300-600 m/s range using two types of spherical projectiles, i.e., rigid and elastoplastic. The results showed that the nacre plate exhibited improved ballistic performance compared to the bulk plate and the plates with continuous layers. The structural design of the nacre plate improved the ballistic performance by producing a more ductile failure and enabling localized energy absorption via the plastic deformation of the tablets and the globalized energy dissipation due to interface debonding and friction. All the plate configurations exhibited a better ballistic performance when impacted by an elastoplastic projectile compared to a rigid one, which is explained by the projectile plastic deformation absorbing some of the impact energy and the enlarged contact area between the projectile and the plates producing more energy absorption by the plates.

Porphyrin-based conjugated microporous adsorbent material for the efficient remediation of hexavalent chromium from the aquatic environment.

The encapsulation and eradication of anions from water have received a lot of scrutinize and are extremely important for virtuous production and environmental treatment. To prepare extremely efficient adsorbents, a highly functionalized and conjugated microporous porphyrin-based adsorbent material (Co-4MPP) was synthesized using the Alder Longo method. Co-4MPP featured a hierarchical microporous and mesoporous layered structure containing nitrogen and oxygen-based functional groups with a specific surface area of 685.209 m2/g and a pore volume of 0.495 cm3/g. Co-4MPP demonstrated a greater Cr (VI) adsorption empathy than the pristine porphyrin-based material did. The effects of various parameters such as pH, dose, time, and temperature were explored on the Cr (VI) adsorption by Co-4MPP. The pseudo-second-order model and the Cr (VI) adsorption kinetics were in agreement (R2 = 0.999). The Langmuir isotherm model matched the Cr (VI) adsorption isotherm, demonstrating the optimum Cr (VI) adsorption capacities: 291.09, 307.42, and 339.17 mg/g at 298K, 312K, and 320K, correspondingly, with remediation effectiveness of 96.88%. The model evaluation further revealed that Cr (VI) adsorption mechanism on Co-4MPP was endothermic, spontaneous, and entropy-rising. The detailed discussion of the adsorption mechanism suggested that it could be a reduction, chelation, and electrostatic interaction, in which the protonated nitrogen and oxygen-containing functional groups on the porphyrin ring interacted with Cr (VI) anions to form a stable complex, thus remediating Cr (VI) anions efficiently. Moreover, Co-4MPP demonstrated strong reusability, maintaining 70% of its Cr (VI) elimination rate after four consecutive adsorptions.

“Wood-nacre”: Development of a Bio-inspired Wood-Based Composite for Beam and 3D-Surface Elements with Improved Failure Mechanisms

Following the natural structure of the nacre, the material studied consists of a multitude of hexagonal tiles that are glued together in an offset manner with a ductile adhesive. This so-called “wood nacre” consists of macroscopic tiles of birch wood veneer with a thickness of 0.8 mm and a size of 20 or 10 mm in diameter in order to mimic the aragonite tiles and the ductile PUR-adhesive corresponds to the layers of collagen in between. E-modulus (MOE), bending strength (MOR) and impact bending strength of the samples were determined and compared with reference samples of birch laminated wood. The hierarchical layered structure of the tiles does not cause any relevant loss in stiffness. Like nacre, “wood nacre” also shows tough fracture behaviour and a high homogenization effect. However, strain hardening and high fracture toughness of the natural model could not be fully achieved. The reason for this is the insufficient ratio between the strength and stiffness of the veneer layers and the adhesive. By adjusting the size of the tiles, increasing the strength and surface roughness of the veneers, e.g. by densification, and using more ductile adhesives that can be applied in smaller layer thicknesses, it should be possible to better reproduce the natural ratios of nacre and thus achieve a significant improvement in the material properties of “wood nacre”. In addition to the mechanical properties, the high potential of the new material lies in the possibility of producing 3D shell-shaped elements for lightweight wood hybrid construction.

Sonochemical construction of hierarchical strontium doped lanthanum trisulfide electrocatalyst: An efficient electrode for highly sensitive detection of ecological pollutant in food and water.

Herbicides are used constantly in agriculture to enhance productivity across the globe. This herbicide monitoring requires utmost importance since its high dose leads to ecological imbalance and a negative impact on the environment. Moreover, a quantification of toxic herbicide is one of the important problems in the food analysis. In this work, deals with the development of a simple, and facile one-pot sonochemical synthesis of strontium doped La2S3 (Sr@La2S3). Morphological and structural characterization confirms the doping of Sr@La2S3 to generate a hierarchical layered structure. The electrochemical performance of modified with rotating disk electrode (RDE) using Sr@La2S3 composite is high, compared to La2S3 and bare electrodes towards the quantitative detection of mesotrione (MTO) in phosphate buffer. Sr@La2S3/RDE showed good sensitivity for MTO detection and it exhibit a range of 0.01-307.01μM and limit of detection of 2.4nM. Besides, the selectivity of fabricated electrode is high as it can electrochemically reduce MTO particularly, even in the presence of other chemicals, biological molecules and inorganic ions. The repeatability of MTO detection is high even after 30days with a lower RSD values. Hence, simple fabrication of Sr@La2S3/RDE could be a novel electrode for the sensitive, selective, and reproducible determination of herbicides in real-time applications.

Hierarchical accordion-like manganese oxide@carbon hybrid with strong interaction heterointerface for high-performance aqueous zinc ion batteries.

Aqueous zinc ion batteries have attracted extensive concern as a promising candidate for large-scale energy storage because of their high theoretical specific capacity, low cost and inherent safety. However, the lacking of applicable cathode materials with outstanding electrochemical performance have severely hindered the further development of aqueous zinc ion batteries. Herein, we report a hierarchical accordion-like manganese oxide@carbon (MnO@C) hybrid with strong interaction heterointerface and comprehensively inquire into its electrochemical performance as cathode materials for aqueous zinc ion batteries. The unique hierarchical accordion-like layered structure coupling with strong interaction heterointerface between small MnO and carbon matrix efficaciously improve the ion/electron transfer process and enhance structure stability of the MnO@C hybrid. Benefitting from these unique advantages, the MnO@C hybrid bestows excellent specific capacity of 456mAhg-1 at 50mAg-1. Impressively, the MnO@C hybrid presents distinguished long-term cycling stability with fairly low decay rates of only 0.0079% per cycle even over 2000 cycles at 2000mAg-1. Moreover, comprehensive characterizations are executed to elucidate the mechanism involved. Therefore, this work affords a new idea for developing outstanding performance manganese-based cathode materials for aqueous zinc ion batteries.

Phase-Tuned MoS2 and Its Hybridization with Perovskite Oxide as Bifunctional Catalyst: A Rationale for Highly Stable and Efficient Water Splitting.

The efficient realization of bifunctional catalysts has immense opportunities in energy conversion technologies such as water splitting. Transition metal dichalcogenides (TMDs) are considered excellent hydrogen evolution catalysts owing to their hierarchical atomic-scale layered structure and feasible phase transition. On the other hand, for efficient oxygen evolution, perovskite oxides offer the best performance based on their rational design and flexible compositional structure. A unique way to achieve an efficient hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in a single-cell configuration is through the hybridization of TMDs with perovskite oxides to form a bifunctional electrocatalyst. Here, we report a simple yet effective strategy to inherently tune the intrinsic properties of a TMD based on MoS2 and its hybridization with LaCoO3 perovskite oxide to deliver enhanced electrocatalytic activity for both the HER and OER. Detailed Raman and XPS measurements highlighted a clear phase transformation of MoS2 from a semiconducting to metallic phase by effectively tailoring the precursor compositions. Based on this, the morphological features yielded an interesting spherical flower-shaped nanostructure with vertically aligned petals of MoS2 with increased surface-active edge sites suitable for the HER. Subsequent hybridization of nanostructured MoS2 with LaCoO3 provides a bifunctional catalytic system with an increased BET surface area of 33.4 m2/g for an overall improvement in water splitting with a low onset potential (HER: 242 mV and OER: 1.6 V @10 mA cm-2) and Tafel slope (HER: 78 mV dec-1; OER: 62.5 mV dec-1). Additionally, the bifunctional catalyst system exhibits long-term stability of up to ∼400 h under continuous operation at a high current density of 50 mA cm-2. These findings will pave the way for developing cost-effective and less complex bifunctional catalysts by simply and inherently tuning the influential material properties for full-cell electrochemical water splitting.

Needle-like Cu(OH)2 in situ grown on nanoporous copper ribbon via anodizing route for supercapacitors

In this paper, Cu–Zr–Ni–Be amorphous alloy was dealloyed to prepare nanoporous coppers (NPCs), which were used as substrate to in situ synthesize needle-like Cu(OH)2@NPC composites via anodization. It's found that the pore size of NPCs increases with the increase of dealloying time and temperature, and the distribution of pores and ligaments becomes more uniform, which indicates that the structure of NPCs can be adjustable. Cu(OH)2 nanowires were in situ grown on the surface of NPC substrate through anodization. The growth process of Cu(OH)2 nanowires is related to the anodization time. As the anodization time increases, the morphology of Cu(OH)2 gradually evolves from nanoneedle to nanobeam and finally to nanoflower. Eventually, three-dimensional hierarchical layered porous structure is formed. The formation mechanism of flower-like Cu(OH)2 is discussed. The needle-like Cu(OH)2@NPC composite possesses excellent conductivity and high capacity, so it can be used as electrode material for supercapacitors. As the current density is 3 mA/cm2, the specific capacitance of the composite electrode is 784 mF/cm2. The needle-like Cu(OH)2@NPC composite exhibits 96% of the initial capacitance after 5000 cycles at 10 mA/cm2, which shows good cycle stability.

Hierarchical NiCo2O4 nanostructured arrays decorated over the porous Ni/C as battery-type electrodes for supercapacitors

The rational construction of hierarchical electrode materials has always been an attractive strategic development in energy storage. In this paper, the porous Ni/C (NC) substrate, which is derived from Ni metal–organic frameworks (Ni-MOFs), is served as the conductive skeleton on Ni foam (NF) for supporting two different morphologies NiCo2O4 nanostructure arrays (NiCo2O4/NC). The hierarchical layered nanomaterial utilizesthe porous NC substrate as “favorable skeleton” for electron transfer and is coupled to vertical well-organized NiCo2O4 nanoarrays to improve specific capacitance of composites. Benefits from the advantages of hierarchical layered structure, the electrochemical properties of as-constructed NiCo2O4/NC with two different morphologies were better than those of pure NiCo2O4 prepared under the same conditions. Moreover, the optimized NiCo2O4 nanowires arrays on NC substrate (NiCo2O4NWs/NC) electrode acquire prominent specific capacitance of 1945.9 F g−1 (270.3 mAh g−1) at 1 A g−1 and good rate performance. Additionally, the assembled asymmetric device by NiCo2O4NWs/NC and carbon nanotube (CNT) displays a high energy density of 58.31 Wh kg−1 at a power density of 749.7 W kg−1, as well as good cyclic stability. The remarkable properties manifest that the hierarchical NiCo2O4NWs/NC electrode has a good prospect in electrochemical applications.

Interlayer functionalization of vermiculite derived silica with hierarchical layered porous structure for stable CO2 adsorption

Cyclic CO2 adsorption via solid amine adsorbents is widely considered as a feasible technology for CO2 mitigation from industrial flue gas. However, the high cost and rapid decline of adsorption capacity and insufficient cyclic stability limit their large-scale application. Herein, we demonstrated a facile and efficient interlayer functionalization approach, involving the synthesis of acid activated expanded vermiculite derived silica (AEV) support with hierarchical layered porous structure and the impregnation of PEI into the AEV support, to enhance CO2 adsorption capacity and cycle stability of AEV/PEI adsorbents. The optimal AEVP50 adsorbent exhibited a high CO2 uptake of 2.21 mmol/g at 75 °C and stable cyclic stability with a mere 1% decay after 10 cycles, owing to the superior hierarchical porous structure of synthesized AEV support. The interlayer functionalization of vermiculite was beneficial for enlarging interlayer volume and producing hierarchical porous structure and abundant Lewis acid sites, which could increase PEI loading content, form uniform amine distribution with less blocked pores/channels and enhance the interfacial interaction between PEI and AEV support. Furthermore, the interlayer spatial confinement effect significantly avoids the inactivation of functional amidogen during the regeneration stage. This strategy significantly enhanced the cyclic CO2 adsorption of AEV/PEI adsorbents through the interlayer functionalization of VMT, and is promising for various practical CO2 capture and separation processes.

Construction of porous NiCo2S4 hierarchical nanoflakes based on zeolitic imidazolate frameworks as battery-type electrodes for high performance supercapacitors

Electrode materials with hierarchical nanoflakes structure show an important application potential in the efficient storage of electrochemical energy. In this work, a bimetallic sulfide NiCo2S4 with a novel controllable structure by adopting a layered double hydroxide (LDH) based on zeolitic imidazolate frameworks (ZIFs) template-oriented strategy is designed. The as-synthesized NiCo2S4 exhibits a hierarchical layered structure composed of nanoparticles with large specific surface area. This unique nanostructure provides abundant electrolyte-accessing sites and sufficient contact between the electroactive materials and electrolytes. As a result, the porous NiCo2S4 electrode exhibits a high specific capacity of 968 C g−1 at 1 A g−1 and an extraordinary rate capability of 91% at the current density of 10 A g−1. Furthermore, a hybrid supercapacitor is assembled with NiCo2S4 as the positive electrode and activated carbon as the negative electrode. The as-prepared device can deliver a high specific energy of 45.1 Wh/Kg at a high specific power of 699.7 W/Kg and its long-term cycling stability can reach 74.7% after 20000 cycles.

Novel highly dispersed Ni-based oxides catalysts for ethanol steam reforming

To prepare high-performance Ethanol Steam Reforming (ESR) catalyst, copper and magnesium were added into NiAl Layered Double Hydroxides (NiAl-LDHs) employing the coprecipitation method as the second and third metals for reducing the sintering of nickel active components and controlling the acid sites. Afterward, NiCuMgAl-LDHs were wrapped on the SiO2 nanospheres to form a spherical layered structure. The results showed that, compared with the NiAl catalyst, after adding Cu metal, resulting from the synergistic effect of Ni–Cu, the ethanol conversion rate increased at different temperature ranges, and ethanol could be wholly converted at 500 °C. With the addition of Mg for neutralize the acid sites of the catalyst, no ethylene, ethanol dehydration product, was produced over the entire reaction temperature range (350–600 °C). NiCuMgAl-LDHs grows vertically on the surface of SiO2 because its hierarchical layered structure is beneficial to inhibit the collapse of laminates, which makes the active components of Ni on SiO2@NiCuMgAl more dispersed and exists edge and corner sites with few coordinative unsaturated active sites, thus exposing of active components and then enhanced performance. Finally, through the catalyst composition and structure optimization, the ethanol was converted entirely, and the stable hydrogen production was realized in the 19 h test.

Immobilizing Ceramic Electrolyte Particles into a Gel Matrix Formed In Situ for Stable Li-Metal Batteries.

Hybrid solid/gel electrolytes (SGEs) have generated much research attentions because of their capability to suppress Li dendrite growth and improve battery safety. However, the interfacial compatibility of the electrode/electrolyte or polymer/inorganic ceramics within hybrid electrolytes remains challenging for practical applications. Herein, an SGE is fabricated by confining ceramic particles (Li7La3Zr2O12; LLZO) into in situ formed tetraethylene glycol dimethyl ether (G4)-based gel electrolytes within assembled cells. A hierarchical layered structure is formed when LLZO settles near the Li anode within the liquid electrolyte during the gradual gelatinization process. Good interfacial compatibility is obtained from good contact with the liquid G4 component. The LLZO layer also serves as an ionic sieve to redistribute the Li deposition. This SGE endows stable Li stripping/plating cycling over 800 h at 0.5 mA/cm2 (60 °C). Moreover, Li-metal batteries with an SGE coupled with LiFePO4 and an air cathode both exhibit superior cycling performance. This work presents a promising strategy for hierarchically layered SGEs for high-performance Li-metal batteries.