Three-dimensional Porous Structure Research Articles

Production of Lignin-Derived Functional Material for Efficient Electromagnetic Wave Absorption with an Ultralow Filler Ratio.

Industrial lignin, a by-product of pulping for papermaking fibers or of second-generation ethanol production, is primarily served as a low-grade combustible energy source. The fabrication of high-value-added functional materials with industrial lignin is still a challenge. Herein, a three-dimensional hierarchical lignin-derived porous carbon (HLPC) was prepared with lignosulfonate as the carbon source and MgCO3 as the template. The uniform mixing of precursor and template agent resulted in the construction of a three-dimensional hierarchical porous structure. HLPC presented excellent electromagnetic wave (EMW) absorption performance. With a low filler content of 7 wt%, HLPC showed a minimum reflection loss (RL) value of -41.8 dB (1.7 mm, 13.8 GHz), and a maximum effective absorption bandwidth (EAB) of 4.53 GHz (1.6 mm). In addition, the enhancement mechanism of HLPC for EMW absorption was also explored through comparing the morphology and electromagnetic parameters of lignin-derived carbon (LC) and lignin-derived porous carbon (LPC). The three-dimensional hierarchical porous structure endowed the carbon with a high pore volume, resulting in an abundant gas-solid interface between air and carbon for interfacial polarization. This structure also provided conductive networks for conduction loss. This work offers a strategy to synthesize biomass-based carbon for high-performance EMW absorption.

Analyzing the preparation, oxidation-related behavior, and electrochemical properties of three-dimensional hierarchical porous WC/C composites

In this study, we prepared biomass porous WC/C composites with a three-dimensional porous structure, and investigated their pore structure, oxidation-related behavior, and electrochemical properties. The results showed that a higher reaction temperature was conducive to the formation of WC on the carbon template. The porous WC/C composites retained the porous structure of the biomass carbon material, and had a large specific surface area (364.19 m2⋅g−1). The overpotential and slope of the Tafel curve of the WC/C composites were lower by 281 mV and 197 mV·dec−1, respectively, than those of the carbon template, while they exhibited a significant increase in electrocatalytic activity. The activation energy of the oxidation reaction of the composites (68.95 kJ⋅mol−1) was higher than that of the carbon template (42.19 kJ⋅mol−1), and their resistance to oxidation improved.

Flower-shaped Ni(OH)2 decorated with biomass-derived carbon TPB-1 for asymmetric supercapacitors

In recent years, notable headway has been made in augmenting supercapacitor functioning through employment of pioneering components, exceptional nanostructures and additional investigation of electrolytes. Nonetheless, achieving superior performance with straightforward techniques remains a significant hurdle. In order to surmount this, an experimental three-dimensional nanospherical pore structure (TPB-20@Ni(OH)2) was designed and prepared. TPB-1 was obtained through carbonisation and activation. TPB-20@Ni(OH)2 nanoparticles were synthesized using TPB-1 as the carbon source and nickel chloride hexahydrate as the nickel source. Furthermore, the TPB-20@Ni(OH)2//AC supercapacitor displayed an impressive energy density of 22.1 Wh kg−1. The TPB-20@Ni(OH)2 composites exhibited a specific capacity of 978 F−1, which is noteworthy. The exceptional output exhibited by the TPB-20@Ni(OH)2 composite derives from its innovative structure, presenting an extensive specific surface area of 237.4 m2 g−1 and porosity of roughly 4.0 nm. Following 20 000 cycles (at a current density of 1 A g−1), asymmetric supercapacitors assembled from TPB-20@Ni(OH)2//AC retained 80.0% of its initial specific electrostatic capacity, indicating superior electrochemical stability and high electrochemical reversibility.

A new multi-functional Cd(II)-organic framework as a platform for high selective fluorescence sensing and dye adsorption

A new three-dimensional porous MOF: {[Cd4(L)2(H2O)6]·(H2O)13·[(H2N(Me)2]2}n was synthesized by solvothermal reaction of 2,4-di(2′,4′-dicarboxyphenyl) benzoic acid ligand with Cd(Ⅱ) metal ion. Cd-MOF has a unique Cd-O metal oxygen chain structure. Metal oxygen chains are connected by ligands to form a three-dimensional porous structure. The solid-state fluorescence spectrum of Cd-MOF shows that the maximum emission peak is at 408 nm. Further liquid fluorescence sensing studies show that the complex can effectively and selectively detect Fe3+, CrO42- and Cr2O72− in aqueous solution with detection limit of 1.77 × 10−4 M, 1.08 × 10−3 M and 1.86 × 10−4 M, respectively, and can be reused five times, so it is a potential fluorescence recognition probe material. The fluorescence quenching mechanism of the system was discussed in detail. At the same time, in the study of the adsorption of dye molecules, it is found that the Cd-MOF has good adsorption capacity for methyl green and methylene blue and can also be used as an excellent dye separation material to selectively adsorb and separate mixed anion and cationic dyes.

Behaviour of alkali-activated fly ash-slag paste at elevated temperatures: An experimental study

As an environmentally friendly material, alkali-activated fly ash-slag (AAFS) is considered as a promising alternative cement because of its excellent mechanical properties and thermal stability. Nevertheless, high temperature induced damage in AAFS can potentially bring serious risks for its practical applications. This paper presents a systematic experimental study on behaviour of AAFS paste subjected to elevated temperatures up to 800 °C in terms of microstructure as well as thermal and mechanical properties. Microstructural evolution was characterised by means of Rietveld-based quantitative X-ray diffraction (QXRD), backscattered scanning electron microscope (BSEM) and X-ray microcomputed tomography (XCT), while thermal and mechanical properties were evaluated from thermogravimetric analysis (TGA), thermal deformation and compressive and flexural strengths. Results indicate that the compressive strength of AAFS paste rises by 77.5 % at 200 °C, followed by a mitigation from 200 to 600 °C and a regain at 800 °C. Different phases in AAFS paste including unreacted particles, reaction products and pores took up 30 %, 67.7 % and 2.31 % at ambient temperature, and 4.95 %, 84.8 % and 10.3 % after exposure to 800 °C, respectively, suggesting the recrystallisation with the formation of nepheline and gehlenite. In addition, the relationships between microstructural characteristics including three-dimensional (3D) pore structure features and thermal and mechanical properties of AAFS paste at elevated temperatures were explored and discussed in depth to gain insights into the underlying degradation mechanisms including pore pressure build-up, thermal gradient and phase transformation.

Mesoporous Bioactive Glass-Graphene Oxide Composite Aerogel with Effective Hemostatic and Antibacterial Activities.

Hemorrhage and infection after emergency trauma are two main factors that cause deaths. It is of great importance to instantly stop bleeding and proceed with antibacterial treatment for saving lives. However, there is still a huge need and challenge to develop materials with functions of both rapid hemostasis and effective antibacterial therapy. Herein, we propose the fabrication of a composite aerogel mainly consisting of mesoporous bioactive glass (MBG) and graphene oxide (GO) through freeze-drying. This composite aerogel has a three-dimensional porous structure, high absorption, good hydrophilicity, and negative zeta potential. Moreover, it exhibits satisfactory hemostatic activities including low BCI, good hemocompatibility, and activation of intrinsic pathways. When applied to rat liver injury bleeding, it can decrease 60% hemostasis time and 75% blood loss amount compared to medical gauze. On the other hand, the composite aerogel shows excellent photothermal antibacterial capacity against Staphylococcus aureus and Escherichia coli. Animal experiments further verify that this composite aerogel can effectively kill bacteria in wound sites via photothermal treatment and promote wound healing. Hence, this MBG-GO composite aerogel makes a great choice for the therapy of emergency trauma with massive hemorrhage and bacterial infection.

One-step sintering construction of electromagnetic synergistic Co7Fe3/Co@CBC nanocomposites for enhanced microwave absorption properties.

Based on the synergistic modulation of electromagnetic parameters and microstructure design, multidimensional porous magnetic carbon-based nanocomposites have become ideal materials with efficient absorption properties. What's more, a carbon-magnetic alloy composite is a commonly used and efficient microwave absorber. In this paper, Co7Fe3/Co@CBC (CFCC) nanocomposites with strong magnetism, a three-phase composition, and a three-dimensional porous structure were synthesized by reducing Fe2+ and Co2+ using chestnut-shell biomass carbon (CBC). Biomass carbon with a higher specific surface area provides numerous active sites for Co7Fe3 nanosheets and Co nanospheres to form three-dimensional ping-pong chrysanthemum-like nanocomposites, which generate rich heterogeneous interfaces and conductive network structures. By adjusting the amount of added biomass, the electromagnetic parameters can be effectively regulated to achieve efficient microwave absorption properties. When the amount of biomass added varies within the range of 1.0 to 2.5 g, all samples exhibit a favorable effective absorption bandwidth (EAB) of over 5.88 GHz. In particular, the CFCC-2.0 composite exhibits optimal microwave absorption properties, with a minimum reflection loss (RLmin) value of -59.25 dB and an EAB of 6.34 GHz at a thickness of 2.8 mm. The simulation and modeling analysis results of radar cross section (RCS) further confirm the exceptional attenuation capability of composite materials at multiple incident angles. The exceptional microwave absorption properties and stability of EAB for the Co7Fe3/Co@CBC nanocomposite make it a promising candidate in the field of absorbing materials. This work also provides some feasible ideas for designing stable broadband wave-absorbing materials.

Acid-modified biomass-based N-doped O-rich hierarchical porous carbon as a high-performance electrode for supercapacitors.

In contemporary society, the conversion and efficient utilization of waste biomass and its derivatives are of great significance. Carbonized wood (CW) is an easily accessible and cost-effective green resource, but it has limitations as an electrode material due to its low specific surface area, limited active sites and poor conductivity. Therefore, it is crucial to improve the performance of biomass-based materials by using activation, heteroatom doping and modification methods to enhance the specific surface area and active sites. In this study, we developed acid-modified urea-doped activated carbonized wood (AUACW) with a three-dimensional (3D) porous structure and porosity, achieving a high specific surface area of 1321.3 m2 g-1. In addition, the degree of graphitization (ID/IG = 1.0) provides good conductivity and a large number of active sites, which are conducive to charge transfer and ion diffusion. The increase of nitrogen and oxygen elements enhances the surface wettability of the material and provides additional pseudocapacitance. The specific capacitance of AUACW reaches 435.84 F g-1 at 0.8 A g-1 with a 93.6% capacitance retention after 10 000 cycles in a 1 M KOH electrolyte. More attractively, a symmetrical supercapacitor (SSC) based on AUACW delivers an energy density of 22.61 W h kg-1 at a power density of 533.26 W kg-1. This work demonstrates the promising potential of utilizing waste biomass to develop green and valuable carbon materials for supercapacitors.

Mn-doped FeOOH modified g-C3N4 as a 3D tubular heterogeneous catalyst for photo-Fenton removal of organic pollutants

To develop environmentally friendly and cost-effective wastewater treatment technologies, a photo-Fenton heterogeneous catalyst Mn-FeOOH/gC3N4 with a three-dimensional porous tubular structure with high catalytic performance was prepared.

Graphyne-based 3D porous structure and its sandwich-type graphene structure for alkali metal ion battery anode materials.

In order to develop candidate materials for more metal ion battery anodes, a three-dimensional (3D) porous structure 3D-PGY was designed based on graphyne, and a sandwich structure graphene/PGY/graphene (G/PGY/G) was constructed by adjusting the distance between two layers of graphene with 3D-PGY as the middle layer. Systematic calculations have shown that 3D-PGY is thermally and mechanically stable even at temperatures up to 1000 K. Li can migrate in multiple diffusion directions in two structures because of its smaller radius while Na and K ions can only migrate through the larger pores. The energy barriers of Li, Na and K ions in 3D-PGY are 0.18, 0.43 and 0.27 eV respectively. After forming the sandwich structure with graphene, the minimum energy barriers of Li, Na and K ions are decreased to 0.12, 0.37 and 0.24 eV, respectively. As the anode for Li, Na, and K ion batteries, the theoretical specific capacities of 3D-PGY are about 558 mA h g-1, and the average open circuit voltages of 3D-PGY and G/PGY/G are about 0.48/0.52/0.29 and 1.08/1.04/1.39 V, respectively. Finally, using ab initio molecular dynamics simulations, the diffusion coefficients for 3D-PGY at different temperatures, as well as for G/PGY/G at 400 K were obtained. The Li, Na and K ions in both structures can diffuse rapidly and have good rate capabilities. These excellent performances show that the graphyne-based 3D porous structure and its sandwich-type graphene structure are very promising for the development of new battery materials.

A flexible pH sensor based on polyaniline@oily polyurethane/polypropylene spunbonded nonwoven fabric.

To fabricate a two-electrode flexible pH sensor based on polypropylene spunbonded nonwoven fabric (PP SF), oily polyurethane (OPU) was first coated on the surface of PP SF to obtain OPU/PP SF. Then, silver/silver chloride (Ag/AgCl) paste, used as the reference electrode and conductive carbon (C) paste were transferred to the OPU/PP SF surface through screen printing. Polyaniline (PANI) was deposited on the surface of the C paste to form a sensing working electrode via the electro-chemical deposition method. The results showed that the surface of the obtained PANI@OPU/PP SF flexible pH sensor (3D PANI pH sensor) presented a three-dimensional (3D) porous network structure. The 3D PANI pH sensor had good mechanical properties, an excellent Nernst response (-67.67 mV pH-1) and linearity (R2 = 0.99) in the pH range from 2.00 to 8.00 in the normal state. In the bent state, the 3D PANI pH sensor retained similar sensitivity (-68.87 mV pH-1) and linearity (R2 = 0.99). Moreover, the 3D PANI pH sensor exhibited a short response time (8 s), excellent reversibility (1.20 mV), low temperature drift (-0.0872 mV pH-1 °C-1) and long-term stability (0.83 mV h-1) in the normal state. Furthermore, the 3D PANI pH sensor can be effectively applied for pH monitoring of liquids and fruits with irregular curved surfaces. The error margin is no more than 0.16 compared to a commercial pH meter.

Metal ion and organic ligand disubstituted bimetallic metal-organic framework nanosheets for high-performance alkaline zinc-based batteries.

Herein, a disubstitution strategy of metal ions and organic ligands is employed to synthesize metal-organic framework (MOF) nanosheets with a three-dimensional (3D) porous structure and a highly active metal-sulfur (M-S, M = Co and Ni) region. The obtained MOFs//Zn batteries exhibit excellent electrochemical properties and the electrochemical reaction mechanism was elucidated through a series of ex situ characterizations.

Hydrogenation of cyclohexene over single-atom Pt or Pd incorporated porous ceria nanoparticles under solvent-free conditions.

In order to maximize the utilization of noble metals in catalysis, single atom of palladium (Pd) and platinum (Pt) were incorporated individually in the framework of porous ceria (CeO2) by using a one-step flash combustion method. Samples with different Pd and Pt loading (0.5, 1, 2.5, and 5 wt%) were prepared and examined by using different analysis techniques such as XRD, ICP, N2 sorption measurements, SEM, HR-TEM, and XPS. The characterization data confirms the formation of zero-state single-atom Pt and Pd (with possible formation of Pd nanoparticles with a size less than 5 nm) incorporated onto the three-dimensional porous ceria structure. The catalytic activity of the synthesized materials was studied in the cyclohexene reduction to cyclohexane at 393 K and 3 atm of pure hydrogen (H2) gas as a model reaction. The obtained results demonstrated that the conversion percentage of cyclohexene is increasing with Pd or Pt loading. The best cyclohexene conversion, 21% and 29%, was achieved over the sample that contains 5 wt% of Pt and Pd, respectively. The collected catalytic data fit the zero-order reaction model, and the rate constant of each catalyst was determined. The catalytic experiments of the most-performed catalysts were repeated five times and the obtained loss in activity was insignificant.

Nano-enzyme functionalized hydrogels promote diabetic wound healing through immune microenvironment modulation.

Non-healing diabetic wounds often culminate in amputation and mortality. The main pathophysiological features in diabetic wounds involve the accumulation of M1-type macrophages and excessive oxidative stress. In this study, we engineered a nano-enzyme functionalized hydrogel by incorporating a magnesium ion-doped molybdenum-based polymetallic oxide (Mg-POM), a novel bioactive nano-enzyme, into a GelMA hydrogel, to obtain the GelMA@Mg-POM system to enhance diabetic wound healing. GelMA@Mg-POM was crosslinked using UV light, yielding a hydrogel with a uniformly porous three-dimensional mesh structure. In vitro experiments showed that GelMA@Mg-POM extraction significantly enhanced human umbilical vein endothelial cell (HUVEC) migration, scavenged ROS, improved the inflammatory microenvironment, induced macrophage reprogramming towards M2, and promoted HUVEC regeneration of CD31 and fibroblast regeneration of type I collagen. In in vivo experiments, diabetic rat wounds treated with GelMA@Mg-POM displayed enhanced granulation tissue genesis and collagen production, as evidenced by HE and Masson staining. Immunohistochemistry demonstrated the ability of GelMA@Mg-POM to mitigate macrophage-associated inflammatory responses and promote angiogenesis. Overall, these findings suggest that GelMA@Mg-POM holds significant promise as a biomaterial for treating diabetic wounds.

Controlled Nitric Oxide-Releasing Nanovehicles for Enhanced Infected Wound Healing: A Study on PDA@BNN6 Encapsulated in GelMA Hydrogel.

The photo-activated thermo/gas antimicrobial nanocomposite hydrogel, Gel/PDA@BNN6, is composed of the nitric oxide (NO) carrier N, N'-di-sec-butyl-N, N'-dinitroso-p-phenylenediamine (BNN6), photothermal (PTT) material polydopamine nanoparticles (PDA NPs), and methacrylate gelatin (GelMA). This hydrogel can release NO gas in a stable and controlled manner, generating a localized photothermal effect when exposed to near-infrared laser light. This dual action promotes the healing of full-thickness skin wounds that are infected. Gel/PDA@BNN6 was developed, and both in vitro and in vivo experiments were carried out to evaluate its structure, physicochemical properties, antibacterial effects, effectiveness in promoting infected wound healing, and biocompatibility. Gel/PDA@BNN6 was successfully synthesized, exhibiting a porous three-dimensional lattice structure and excellent mechanical properties. It demonstrated highly efficient photothermal conversion, controllable nitric oxide delivery, strong bactericidal effects, and minimal cytotoxicity in vitro. In vivo, Gel/PDA@BNN6, when used with NIR therapy, showed significant anti-inflammatory effects, promoted collagen deposition, and stimulated vascular neoangiogenesis, which accelerated wound closure. Additionally, it displayed superior biocompatibility. Gel/PDA@BNN6has shown an explicit curative effect for infected wound healing, suggesting it has a good chance of being an antimicrobial dressing in the future.

Decellularization of caprine forestomach rumen tissue modified with silver nanowires as an antibacterial skin substitute scaffold in wound care therapeutics.

In this study, caprine forestomach native collagen (CFNC) isolated from rumen tissues is reported for the first time with subsequent surface modifications with varying concentrations of silver nanowires (AgNWs). Accordingly, CFNC/AgNWs scaffolds were prepared to be used as suitable wound healing dressing materials through a sequential isolation and decellularization process, followed by step-wise AgNW surface modification and ultraviolet (UV) crosslinking. The significant outcomes of this research highlight that CFNC/AgNWs scaffolds exhibit a highly porous three-dimensional (3D) network structure with favourable physicochemical characteristics. Also, the comprehensive tensile testing demonstrated that there were changes in mechanical properties based on the AgNW content. The CFNC/AgNWs scaffolds also exhibited strong antibacterial action against E. coli and S. aureus in a dose-dependent manner. The release of Ag+ ions from CFNC/AgNWs scaffolds exhibited a slow and sustained release pattern over an extended period of time. The cell-biomaterial interaction studies on CFNC/AgNWs scaffolds using L929 fibroblast cells showed dose-dependent and time-dependent toxicity when the concentration exceeded above 1 mg mL-1. The cytotoxicity is mainly due to the higher concentration of Ag+ ions which initiates cell death through lipid peroxidation and causes cell membrane damage. The biocompatibility test results serve as a reference point to select the optimal dosage of AgNWs with balanced antibacterial and biocompatibility properties. Thus, the developed CFNC/AgNWs scaffolds will serve as a versatile wound dressing material similar to other metallic or conjugated reconstituted collagen systems with the added benefit of strong antimicrobial properties, and as a biomimetic xenograft for skin regeneration.

Unveiling the potential of HKUST-1: synthesis, activation, advantages and biomedical applications.

Metal-organic frameworks (MOFs) have emerged as a unique class of nanostructured materials, resulting from the self-assembly of metal ions or clusters with organic ligands, offering a wide range of applications in fields such as drug delivery, gas catalysis, and electrochemical sensing. Among them, HKUST-1, a copper-based MOF, has gained substantial attention due to its remarkable three-dimensional porous structure. Comprising copper ions and benzene-1,3,5-tricarboxylic acid, HKUST-1 exhibits an extraordinary specific surface area and pronounced porosity, making it a promising candidate in biomedicine. Notably, the incorporation of copper ions endows HKUST-1 with noteworthy activities, including antitumor, antibacterial, and wound healing-promoting properties. In this comprehensive review, we delve into the various synthesis methods and activation pathways employed in the preparation of HKUST-1. We also explore the distinct advantages of HKUST-1 in terms of its structural properties and functionalities. Furthermore, we investigate the exciting and rapidly evolving biomedical applications of HKUST-1. From its role in tumor treatment to its antibacterial effects and its ability to promote wound healing, we showcase the multifaceted potential of HKUST-1 in addressing critical challenges in biomedicine.

Efficient sulfur atom-doped three-dimensional porous MXene-assisted sodium ion batteries.

Recently, it has been reported that MXene is a promising pseudocapacitive material for energy storage, primarily due to its intercalation mechanism. However, Ti3C2Tx MXenes face challenges, such as inadequate layer spacing and low specific capacity, which greatly hinder their potential as anode materials for sodium storage. In this study, MXene was doped with sulfur to create a three-dimensional porous structure that resulted in an increased layer spacing. The sulfur-doped porous MXene (SPM) demonstrated exceptional performance as sodium ion battery anodes, with a capacity of 335.2 mA h g-1 after 490 cycles at 2 A g-1 and a long-term cycling performance of 256.1 mA h g-1 even after 2480 cycles at 5 A g-1. It is worth noting that the porous structure formed after sulfur-doping exhibits superior sodium storage performance compared to previously reported MXene-based electrodes. This highlights the feasibility of the structural construction strategy, offering an effective solution for energy storage and conversion applications.

Computer simulation of a solar multi-effect distillation multi-stage flash effluent purification system

Abstract This study integrates multi-effect distillation (MED), multi-stage flash (MSF) evaporation, and solar interface evaporation technologies to enhance water purification processes. We evaluate the material and performance of interface evaporators, with a particular focus on managing the energy balance in solar water evaporation. The research further develops thermal regulation in photothermal materials to maximize light absorption, minimize heat loss, and speed up steam conversion. We employ a novel approach using corn starch and ionic liquid-modified silica hydrogels, noted for their hydrophilicity and broad-spectrum light absorption. The goal is to assess these hydrogels for photothermal conversion efficiency and salt resistance, examining their evaporation performance across various media—pure water, highly saline water, and oily wastewater—and their effectiveness in purifying industrial sewage. Monomer [VEIm]Br and cross-linking agent polymerization occurred to prepare the obtained SiO 2 – PILs.Ag / PPy / SiO 2 – PILs surface of polypyrrole and Ag particles presenting a three-dimensional porous structure is able to enhance the light absorption performance, between 200-2500 nm range of light absorption rate as high as 90%. Experiments proved the introduction of ionic liquid grafted silica on the introduction of the mechanism to improve the thermal insulation and salt resistance for the actual wastewater purification to provide a strategy.

A flexible piezoresistive pressure sensor based on a perovskite MAPbBr3 nanocrystal-embedded polymer composite

The three-dimensional porous structure of the material is adjusted by adding perovskites, and a flexible pressure sensor is constructed in a “sandwich” structure to detect human facial expression, pulse, breathing, and joint movement.