Three-dimensional Honeycomb Research Articles

Highly Efficient and Selective Hydrodeoxygenation of Guaiacol Using Ni-Supported Honeycomb-Structured Biochar and Phosphomolybdic Acid.

The sustainable development of energy has always been a concern. Upgrading biomass catalysis into hydrocarbon liquid fuels is one of the effective methods. In order to upgrade biomass derivative guaiacol by Hydrodeoxygenation (HDO) catalysis, this article report a three-dimensional honeycomb structure biochar loaded with Ni nanoparticles and phosphomolybdic acid demonstrating excellent catalytic performance in a short period of time. This is due to the porous structure of biochar, which allows Ni metal nanoparticles to be highly uniformly dispersed on the support, which enhances the catalytic hydrogenation of guaiacol in terms of both rate and efficiency. Furthermore, it was observed that the added phosphomolybdic acid dissolved within the temperature range of 78-90°C, functioning as a homogeneous catalyst in the process. This proves advantageous, as the phosphomolybdic acid becomes accessible at any location within the porous Ni/C catalyst. The detailed characterization data revealed that the carbon support prepared in this study has a high specific surface area of up to 1375.61 m2/g. Additionally, the phosphomolybdic acid exhibited rich acidity, with Brønsted and Lewis acid contents of 2.55 μmol/g and 21.45 μmol/g, respectively. Reaction data demonstrated that at 240°C for 180 minutes, 100% conversion and 97.9% cyclohexane selectivity were achieved.

Effects of phosphorylation-modified long-chain inulin on wheat starch: Physicochemical properties and retrogradation behaviors

In this research, modification of long-chain inulin (FXL) through phosphorylation (PFXL) to enhance its application in wheat starch (WS) and starch-based products. The impacts of PFXL on the pasting, rheology, microstructure, and retrogradation characteristics of WS were researched. The findings revealed that PFXL significantly reduced both the breakdown and setback values of WS. Additionally, the incorporation of PFXL reduced the viscoelasticity of WS paste and improved its fluidity. Scanning electron microscopy indicated that higher PFXL levels (>5 %) produced small fragments that partially covered the three-dimensional honeycomb structure of WS paste, thereby reducing water loss during short-term storage. PFXL also altered water distribution in WS gels, depending on concentration and storage duration. X-ray diffraction and Fourier-transform infrared spectroscopy suggested that PFXL effectively inhibited amylopectin recrystallization. Compared to FXL, PFXL exhibited a more pronounced ability to inhibit the aging of WS in short- and long-term storage.

Genetic-algorithm-assisted design of chiral honeycomb membrane acoustic metamaterials for broadband noise suppression

Low-frequency sound wave reduction is hardly feasible for traditional sound absorbers such as porous media. In contrast, locally resonant acoustic metamaterials act as spatial frequency filters, effectively reducing low-frequency noise. However, these materials can have narrow bandgaps, add extra mass to the main system, and function only within a specifically adjusted frequency range. Therefore, this paper proposes a methodology for designing three-dimensional (3D) chiral honeycomb membrane-type acoustic metamaterials (MAM) based on acoustic circular dichroism (ACD), negative effective mass, and local resonance mechanisms (LRM). The paper also uses the genetic algorithm (GA) to maximize sound transmission attenuation and widen bandgaps. The accuracy of the simulations is validated with available experimental data. The key idea of the present study is to automatically design a MAM structure using modern optimization tools. A developed GA aims to maximize the average sound transmission loss (STL) across the desired low-frequency range of 0–850 Hz by optimizing the value of structural parameters associated with the configurations of masses, including rotation and linear offset, as well as their geometrical dimensions, including length and width. COMSOL Livelink with MATLAB is employed as a practical co-simulation tool to find an optimum value for structural parameters. Results indicate a 35% improvement in average STL along with an ultra-wide bandgap with a 507% bandgap coverage factor (BGCF) in the frequency range of interest, verifying the reliability of the developed algorithm. In addition, sound mitigation incidence is justified by exploring the negative effective parameters of the unit cell and displacement vector fields. The proposed designs demonstrate superior performance as both initial and optimized models broke the mass law within the investigated frequency range. Finally, the effect of the selected geometrical parameters on the objective function is observed through sensitivity analysis. This study presents the practical use of optimization algorithms to develop MAMs.

Design-manufacturing-performance of electromagnetic absorbing/load bearing three-dimensional honeycomb woven composites

Structural electromagnetic wave (EMW) absorbing composites play a critical role in both civilian and military applications. However, traditional sandwich honeycomb EMW absorbing composites have poor out-of-plane mechanical properties and load-bearing performance.This study introduces the development of a three-dimensional honeycomb woven composite (3DHWC) that integrates EMW absorption and load-bearing capabilities. A weaving loom was used to fabricate a three-dimensional honeycomb woven structure fabric (3DHSWF) with varying structural parameters. Subsequently, the composites were formed using carbon black (CB), multi-walled carbon nanotubes (MWCNTs), and carbonyl iron powder (CIP) as hybrid absorbers, epoxy resin as the matrix, combined with the vacuum-assisted resin transfer molding (VARTM) process. Testing confirmed the material’s excellent EMW absorption and mechanical properties, achieving a maximum reflection loss (RL) of −30.9 dB and an adequate EMW absorption bandwidth (EAB) of 14.58 GHz. The maximum bending load reached 5799.1 N, with no delamination observed in the samples. This material demonstrates outstanding EMW absorption performance and exhibits superior load-bearing capacity while maintaining structural integrity. Our research provides valuable insights into the design of honeycomb EMW absorbing composites, offering significant advancements in EMW absorption efficiency and bending mechanical properties.

Comprehensive analysis of charge carriers dynamics through the honeycomb structure of graphite thin films and polymer graphite with applications in cold field emission and scanning tunneling microscopy

Polymer graphite electron sources have performed satisfactorily as field emission emitters and scanning tunneling microscopy probes in the past few years. However, the emission process was characterized by limited total emission currents. This paper introduces the elemental, vibrational, electronic structure, and optical analysis of polymer graphite and glass-graphite composite field emission cathodes to study these limitations. Moreover, the field emission characteristics are studied including the changes in the potential energy barrier of the used materials and structures. Among the studied structures, the cathodes prepared from graphite thin films deposited on a micropointed glass substrate (film-GMF) showed superior performance as random field emission arrays. This includes obtaining much higher emission current values ≈ 20 times) and lower threshold voltages ≈ 1/2) compared to the results obtained from polymer graphite samples. The enhancement factor in such emitters is believed to be the three-dimensional honeycomb structure of graphite. Moreover, the study includes applying graphite coatings to tungsten nano-field emission cathodes and scanning tunneling microscopy probes, which improves the performance of such cathodes/probes in both microscopic techniques.

Breaking new ground in metal-ion battery anodes: First principles design of Dirac nodal line semimetallic carbon materials

With the rapid development of electronic devices, the demand for batteries has gradually increased, and existing batteries can no longer satisfy it. In this paper, a three-dimensional honeycomb carbon material is designed and termed pmma-C32. The mechanical stability, dynamic stability, thermal stability, and mechanical stability were investigated through first-principles molecular dynamics, phonon spectrum, and the Born-Huangkun criterion. The calculation results show that pmma-C32 not only has good thermodynamic stability, but also has static stability. Similar to graphene, pmma-C32 exhibits semi-metallic characteristics, featuring two Dirac node lines with high Fermi velocity, indicating a high capacity for electron transport. As a metal-ion battery material, pmma-C32 exhibits higher theoretical capacity(836.8, 732.2, and 418.4 mA h/g for Li, Na, and K), lower diffusion barrier (0.06–0.12 eV for Li, 0.10–0.11 eV for Na, and 0.05–0.06 eV for K), and lower open circuit voltage (0.34 V for Li, 0.37 V for Na, and 0.74 V for K). These remarkable properties endow semimetallic pmma-C32 as a promising anode material for metal-ion batteries, providing fast charge and discharge rates. This research not only broadens the family of three-dimensional carbon materials, but also greatly improves the performance for universal metal-ion battery anode materials through material structure design.

Experimental study on selected properties and microstructure of pine-based wood ceramics

Abstract Wood ceramics using biomass materials as templates possess the benefits of facile fabrication and versatile applicability. To investigate the physical properties, chemical properties and microstructure of wood ceramics prepared from biomass materials, the basic properties and potential applications of wood ceramics were expounded. In this paper, wood powder wood ceramics (WPWC) and wood fiber wood ceramics (WFWC) were prepared through the vacuum carbonization method, utilizing pine powder and pine fiber as raw materials. The impact of phenolic resin concentration and mixture filling mass on various properties of wood ceramics, including mass loss rate (MLR), volume shrinkage rate (VSR), apparent porosity (AP), and bending strength (BS) were investigated on this basis. The microtopography and pore structure of wood ceramics were also analyzed. The test results show that an increase in the concentration of phenolic resin led to a decrease in the MLR, VSR, and AP of WPWC and WFWC, while their BS exhibited an increase. When the concentration of phenolic resin was 60 %, the phenolic resin yielded a BS of 8.70 MPa and 9.20 MPa for WPWC and WFWC, respectively. Furthermore, the microstructures of both WPFC and WFWC reveal hierarchical porous structures. The difference is that WPFC has a dispersed three-dimensional network topology in its overall morphology, which is mainly formed by filamentous or long linear glass carbon in wood ceramics dominated by carbon. The natural and consistent pore structure of WFWC is comparable to a three-dimensional honeycomb structure, the primary mesoporous size was around 40.28 nm and the main macropore size was more than 10,000 nm. It elucidates the pore structure of WPWC and WFWC, characterized by “hierarchical porosity”, the differences and relationships between porous wood ceramics derived from powdery and fibrous biomass as raw materials were analyzed, which contributes to the advancement of the fundamental principles of wood ceramics and establishes a theoretical basis for the practical exploration and development of biomass materials.

A novel coupling-induced strength-improved three-dimensional honeycomb with positive-negative dual Poisson's ratios

By combining the Re-entrant (RE) cell with the hexagonal (HE) cell, this study proposes a novel three-dimensional honeycomb called Re-entrant-hexagonal-coupling (RHC) honeycomb to improve the strength of a single structure. The deformation modes and the strength of the honeycomb are comprehensively investigated through experimental and numerical methods. Results indicate that the deformation of the RHC honeycomb exhibits a clear coupling effect due to the opposite deformation of the RE and HE honeycombs, resulting in a quasi-zero Poisson's ratio mode and a significant strength enhancement. The coupling-induced enhancement (CIE) of the RHC honeycomb remains consistently higher than 0.585, demonstrating clear superiority over the other two comparative honeycombs. Besides, adjusting the thickness ratio can effectively balance the coupling effect and auxetic effect, thereby enhancing the specific energy absorption at a given relative density. This study offers valuable guidance for the design and research of such coupling auxetic honeycomb structures, warranting further attention.

Design and testing of novel three-dimensional modular negative stiffness honeycomb structures as reusable crash absorbers

Conventional crash absorbers dissipate kinetic energy of impacts into plastic irreversible deformation, needing an immediate replacement to restore safety of the structure, highly increasing cost and inconvenience of the system. Aim of the present work was to develop innovative prototypes of reusable crash absorbers, able to withstand multiple collisions . A novel design was proposed, based on a modified Negative Stiffness Honeycomb (NSH) approach, using a three-dimensional modular layout with the objective of improving performance, reliability, and functionality of the device in repeated impacts. Two prototypes were manufactured to prove the concept. The first was produced in Nylon PA 6/66 by fused deposition modelling, while the second was obtained from laser-cut plates of stainless steel AISI 304. The nylon prototype was evaluated in cyclic static compression and dynamic impact tests, while the performance of the steel prototype was assessed only in impact tests. Results show improved values of energy absorption with respect to previous studies using bidimensional NSH energy absorbers and a highly reliable behaviour in multiple dynamic compression tests. Moreover, the nylon prototype featured a novel behaviour during impact tests, with autonomous delayed recovery of deformation after the collision. Our data show that three-dimensional modular NSH approach is effective in obtaining a reusable crash absorber, with improved performance and functionality compared to previously proposed design. This work can be considered a step forward in the search for alternative crash absorbers able to sustain multiple impactsbefore substitution, with potential advantages when their replacement is either impossible or too expensive.

Nano-silicon embedded in 3D honeycomb carbon frameworks as a high-performance lithium-ion-battery anode

The fabrication of three-dimensional (3D) honeycomb carbon frameworks, incorporating embedded silicon (Si) nanoparticles (NPs), is successfully achieved through a facile method involving mixing, carbonization, and acid pickling. The as-prepared Si@PVPC composites exhibit excellent electrochemical performances due to reasons as follows. (1) Honeycomb channels supply enough space to accommodate the expansion of Si NPs and so structural integrity of 3D honeycomb carbon frameworks are maintained during lithiation/delithiation processes. (2) Honeycomb channels offers fast transfer paths for Li-ion diffusion. (3) 3D carbon frameworks afford reliable and stable electric contact points. As a result, Si@PVPC electrodes show a capacity of 1294.3 mAh g−1 at 2 A g−1 after 1400 cycles with a capacity retention of 85.5 %. Even at an ultrahigh current of 16 A g−1, Si@PVPC electrodes still show a capacity of 619.6 mAh g−1.

Investigation of bending behavior of two and three-dimensional honeycomb and auxetic sandwich beams

The bending behavior of two (2D) and three-dimensional (3D) sandwich beams that have a negative Poisson’s ratio (auxetic) and conventional honeycomb was investigated for different geometries, sheet thicknesses, and cell thicknesses. The re-entrant and solid specimens were produced with a stereolithographic (SLA) 3D printer and subjected to a three-point bending test under the conditions specified in the ASTM C393 standard. The data obtained from the tests were used to verify finite element analysis (FEA) results. The radius of curvatures was calculated for each specimen depending on the load step. In addition, Poisson’s ratio was calculated for each auxetic sample. As a result, the 3D arrowhead beam, with a cell thickness of 1 mm and a sheet thickness of 2 mm, exhibits peak force values that are 497.340% and 461.500% higher than re-entrant and missing rib beams, respectively. Besides, the maximum strain energy values of same 3D arrowhead specimens (596.120 mJ) are higher than re-entrant (101.032 mJ) and missing rib (108.201 mJ) specimens. It was determined that the arrowhead is the most durable structure compared to other auxetic structure geometries. Therefore, when arrowhead and honeycomb 3D beams are compared, it was observed that the maximum strain energy of arrowhead specimens was higher in both horizontal (84.310%) and perpendicular (131.910%) positioned specimens. Comparing the arrowhead and honeycomb 2D beams with the highest maximum strain energy, it can be concluded that the arrowhead beam absorbs 20.000% more energy.

Two-dimensional Ti3C2Tx anchored on three-dimensional SiC honeycomb framework for efficient and cyclic photocatalytic degradation of organic pollutants

The excellent recyclability of SiC foam renders it an ideal catalyst in the field of photocatalytic degradation, however to further improve its photocatalytic efficiency remains a major challenge in current research. In this regard, a honeycomb-like porous SiC foam was successfully constructed through freeze-drying and polymer-to-ceramic derivation method, with two-dimensional Ti3C2Tx nanosheets anchored on its three-dimensional framework. Their photocatalytic performances were evaluated by the degradation of methylene blue (MB) under visible-light irradiation. All Ti3C2Tx/SiC hybrid foams show superior photocatalytic degradation capability compared with SiC foam, with a highest removal rate (adsorption and degradation) reaching 94.4% for TSF-4, denoting an increasement of 50.4%. Even after five cycles, the removal rate remained at 91.4% with only a slightly loss of 3%, suggesting its excellent recycling performance. These desirable results stem from the unique structural design, in which the porous structure facilitates the contact between catalyst and pollutant, while the Ti3C2Tx/SiC heterojunction promotes effective separation of photogenerated carriers. This work paves the way for the development of lightweight, efficient and easily recyclable photocatalyst for wastewater purification.

Exploring the effect of different precursor materials on Fe-loaded biochar catalysts for toluene removal

Rice husks, camphor tree leaves, and corn stalks were selected as raw materials from shell, leaf, and stem biomass, respectively, to prepare Fe-loaded biochar catalysts, and the removal efficiency of toluene by the three catalysts was determined. The removal efficiencies of shell catalyst (ARHB-Fe) and stem catalyst (ACSB-Fe) were 89.68% and 90.97%, respectively, both lower than that of leaf catalyst (ACLB-Fe), which was 92.01%. ARHB-Fe and ACSB-Fe exhibited a fibrous structure, while ACLB-Fe exhibited a three-dimensional honeycomb structure. ARHB-Fe had the largest specific surface area at 284.65 m²/g, exhibiting excellent physical adsorption performance for toluene. A cross-comparison of the existing forms of Fe in the three catalysts was conducted. The highest Fe2+ content in ARHB-Fe was 45.64%. The highest Fe3+ content in ACLB-Fe was 46.76%. Fe3+ underwent electrostatic reactions with the benzene ring, enhancing the adsorption of toluene. The highest Fe3C content in ACSB-Fe was 18.20%. At high temperatures, Fe3C decomposed to produce Fe0, possessing strong reducing ability and high reactivity, which effectively promoted the catalytic cracking of toluene. ARHB-Fe and ACSB-Fe were mainly influenced by n–π interactions (C–O functional groups). ACLB-Fe exhibited the combined effects of hydrogen bonding interactions (–OH functional groups), n–π interactions, and π–π interactions (CC functional groups). Furthermore, ACLB-Fe possessed the most abundant acidic sites and the highest acidity.

Three-dimensional honeycomb composites consist of metal carbides and layered double hydroxides for high-performance supercapacitor electrode materials

To achieve excellent electrochemical performance and stability, a composite material based on metal carbides (MXene) and CoNiZn layered double hydroxides (LDHs) has been synthesized, which synergistically combines the high electrical conductivity of MXene with the high theoretical specific capacity of LDHs. The as-prepared three-dimensional honeycomb-structural MXene/CoNiZn LDH composites have excellent cycle stability with a capacitance retention rate of 87.8% after 100,000 cycles and outstanding electrochemical activity with a specific capacitance of 2044.9 F g−1 at a scan rate of 5 mV s−1. Furthermore, electrochemical impedance spectroscopy also shows a reduced internal resistance indicating that the honeycomb-porous structure facilitates electron transfer and ion diffusion. This study provides a feasible route to develop high-performance supercapacitor electrode materials.

A novel three-dimensional orthogonal star honeycomb structure with negative Poisson’s ratio

A novel three-dimensional(3D) orthogonal star honeycomb structure with increased strength and negative Poisson’s ratio(NPR) performance that is not subject to angle constraints was proposed, and the calculation model of Young’s modulus and Poisson’s ratio of the cell structure under axial load was derived in this study. Through the investigation of the deformation mode and the finite element (FE) research results of the structure, it is found that the longitudinal length parameter l2 and angle parameter θ2 are important concave axes that affect the mechanical properties of materials. The quasi-static compression experimental results shows that the constraints of adjacent elements can enhance the strength of the structure to a certain extent, and the theoretical analysis results and the FE simulation results were in good agreement with the experimental results. In addition, the results are also concluded that the prediction of Young’s modulus and Poisson’s ratio and the designability of mechanical properties of 3D orthogonal star honeycomb structures could be achieved by the theoretical calculation formula derived in this study.

Robust three-dimensional bioinspired honeycomb structured ultra-elastic aerogels for high-temperature cascade filtration applications

High-temperature particulate matter (PM), commonly produced by daily power generation, industrial smokestacks, and vehicle exhaust emissions, causes a significant risk to public health and environmental sustainability. The current strategy for solving these problems is to utilize adsorption filtration technology. In this work, we successfully constructed a bioinspired honeycomb structured aerogel with nano/micron fiber-reinforced polyimide gradient by using two strategies of fiber-reinforced filler and stepwise directional freezing technique. It overcomes the high shrinkage of polyimide aerogel and exhibits super elastic recovery performance without damage after 100 compression cycles at 50% strain, as well as high flame-retardancy and low thermal conductivity (32.14 mW m−1 K−1). Meanwhile, it shows excellent air filtration efficiency of about 97% and pressure drop of about 90 Pa after 50 cycles, as well as an excellent oil/organic solvent absorption performance and recoverability. In principle, the gradient structure with gradual change shows the “medium pore-small pore” cascade interception effect in the direction of airflow velocity propagation, which successfully achieves the selective and precise interception of polydisperse particles and the stratified accumulation of particles. It further significantly extends the filter service life and provides new insights into the upgrade of new high-temperature filters with significant research implications.

From π-conjugated macrocycles to heterocycloarenes based on benzo[2,1-b:3,4-b']dithiophene (BDTh): size- and geometry-dependent host-guest properties.

π-Conjugated macrocycles have been highly attractive due to their challenging synthesis, fascinating aesthetic structure and unique physical and chemical properties. Although some progress has been made in synthesis, the study of π-macrocycles with different structural characteristics and supramolecular interactions still faces major challenges. In this paper, two new single-bond linked macrocycles (MS-4T/MS-6T) were reported, and the corresponding vinyl-bridged heterocycloarenes (MF-4T/MF-6T) were synthesized by the periphery fusion strategy. Further studies have indicated that the structure of these four macrocycles is determined by both size and curvature, showing unique variations from nearly planar to bowl and then to saddle. Interestingly, the nearly planar MS-4T with a small size and the rigid saddle-shaped MF-6T show no obvious response to fullerenes C60 or C70, while the bowl-shaped MS-6T and MF-4T demonstrate a strong binding affinity towards fullerenes C60 and C70. What's more, two kinds of co-crystals with capsule-like configurations, MS-6T@C60 and MS-6T@C70, have been successfully obtained, among which the former shows a loose columnar arrangement while the latter displays a unique three-dimensional honeycomb arrangement that is extremely rare in supramolecular complexes. This work systematically studies the π-conjugated macrocycles and provides a new idea for the development of novel host-guest systems and further multifunctional applications.

Kirigami-inspired organic and inorganic film-based flexible thermoelectric devices with built-in heat sink

Thermoelectric (TE) devices can convert heat to electricity directly, which offers a unique opportunity to realize waste heat recovery. However, conventional TE devices inevitably use heat sinks, which are bulky, rigid and heavy, limiting practical applications. Herein, we propose a fully integrated film-based TE device with intrinsically built-in fins as heat sink in a hexagonal honeycomb device structure, that simultaneously achieves high TE performance and conformability, as confirmed by experiments and modelling. A flexible Kapton substrate with copper electrodes, integrating either carbon nanotube (CNT) veils or bismuth telluride (Bi2Te3) TE ‘legs’, both of n- and p-type, achieved a remarkable specific power of 185.4 nW K−2 for a Bi2Te3-based device and 53.1 nW K−2 for a CNT-based device, thanks to the heat dissipation effect granted by the built-in fins. Besides, the addition of oriented polymer films interconnects, contracting when above their glass transition temperature, allowed a single substrate two-dimensional (2D) TE device to self-fold into a three-dimensional (3D) hexagonal honeycomb structure, with built-in fins, contactlessly and autonomously. The demonstrated shape-programmed kirigami-inspired scalable TE device paves the way for realising self-powered applications comprising hundreds of TE legs with both inorganic (e.g., Bi2Te3) and organic (e.g. CNT veils) TE materials and integrated heat sinks.

Acoustic Shock Wave-Induced Solid-State Fusion of Nanoparticles: A Case Study of the Conversion of One-Dimensional Rod Shape into Three-Dimensional Honeycomb Nanostructures of CdO for High-Performance Energy Storage Materials.

Herein, we describe the solid-state fusion of rod-shaped to honeycomb-shaped cadmium oxide particles (CdO NPs) caused by the process of repeated exposure to acoustic shock waves. Significant changes have been observed in structurally and morphologically dependent properties. For instance, at the 200-shocked condition, the high-pressure CdO-B2 phase is present as a secondary phase wherein all of the rod-shaped particles have been transformed into honeycomb-shaped CdO particles which possess comparatively higher specific-capacitance than CdO nanorods (NRs). The computed specific capacitance values for the 0, 100, and 200 shocked samples at a scan rate of 100 m V s-1 are computed to be 433, 415, and 583 F g-1, respectively. The second-stage decomposition temperature points of the CdO NPs have significantly increased in accordance with the morphological changes from rod to honeycomb patterns such that the values are 343, 526, and 534 °C, respectively, for 0, 100, and 200 shocked conditions. Note that such honeycomb nanostructured CdO particles by shock-wave processing have never been observed, to date. Due to the superior energy storage abilities as well as the spectacular high thermal stability of the honeycomb CdO nanostructures compared to CdO NRs, shocked CdO with honeycomb nanostructures can be considered as energy storage materials.

Ultra-thin nanohoneycomb porous CoMoO4 with excellent catalytic performance for water splitting at large current densities

Electrocatalytic water splitting for hydrogen production is considered the most effective and cleanest strategy to make full use of renewable energy. It still lacks the highly efficient and stable bifunctional catalyst to deliver high current density for large scale application of water splitting. Here, we innovatively developed a facile method to synthesize a three-dimensional (3D) honeycomb porous CoMoO4@pNi (porous nickel) catalyst with ultra-thin nanosheet, the generated oxygen vacancies and mesoporous structures with defects as active sites. We also precisely tuned the thickness and array structure to investigate its catalytic performance. The as-prepared CoMoO4@pNi catalyst delivers the overpotential of 377 mV for HER and 410 mV for OER, respectively, and only demands 1.99 V to reach a large current density of 1000 mA cm−2 for overall water splitting. CoMoO4@pNi catalyst is also operated for 200 h under 500 and 1000 mA cm−2, respectively, and both showed an ignorable current decrease. The excellent activity and stability are ascribed to the high surface area, short transport path for electrons and protons, the full contact between the exposed active sites and electrolyte, and the inherent stable nanohoneycomb porous structure of the ultra-thin nanosheet.