Journal of Porous Materials最新文献

Crack-free silica aerogel monoliths with the desired properties were successfully synthesized via a custom-built autoclave. The impact of the synthesis environment on the morphological, optical, and thermal properties of the synthesized monoliths was examined. The autoclave successfully produced an aerogel monolith with a surface area of up to 998.25 g/m², a thermal conductivity of 0.0053 mW·m⁻¹ K^− 1 °C, and a density of 0.047 g/cm³. The samples were examined through SEM and BET measurements. These investigations revealed that density, porosity, and optical permeability are significantly influenced by the initial pH and its impact on the final microscopic structure. The absence of a catalyst during the preparation of aerogels resulted in the production of dense, opaque monoliths with reduced porosity. The environment, with a pH of 8, significantly affected the characteristics and properties of the aerogel, The acidity of the reaction environment progressively influenced the final properties of the aerogel. It cannot be denied that this is essential to accomplish the required optical and nanoparticles.

This study investigates the synthesis and characterization of a novel magnetic mesoporous silica nanoparticle (MMS) platform, specifically Fe₃O₄@SiO₂@KCC-1, functionalized for the immobilization of the diaphorase enzyme. We developed a unique core-shell structure by integrating the superparamagnetic Fe₃O₄ core with the hierarchical, fibrous KCC-1 mesoporous silica, followed by sequential functionalization with amine groups, cyanuric chloride, and diaphorase (MMS-NH₂@CC-enz). Characterization techniques, including nitrogen adsorption-desorption isotherms, FT-IR, XRD, TGA, VSM, and FE-SEM, confirmed the successful synthesis and functionalization, preserving the mesoporous structure while reducing pore size, indicative of effective modification. The novelty of this work lies in the enhanced stability and activity of immobilized diaphorase, demonstrating improved thermal, pH, and storage stability, as well as reusability up to 5 cycles with significant activity retention. Kinetic and thermodynamic analyses revealed subtle changes in K_m, V_max, and thermodynamic parameters (E_a, ΔH, ΔG, ΔS), offering new insights into enzyme-nanoparticle interactions on this magnetic KCC-1-based support. This research introduces a multifunctional MMS platform as an innovative carrier for enzyme immobilization, with significant implications for biotechnological applications such as biosensing, biocatalysis, and bioremediation.

The application of nitrogen-rich metal–organic framework (N-rich MOF) and its magnetic composite in the aza-Michael reaction as a catalyst was investigated. The synthesis of anionic N-rich MOF, [CuBT(H₂O)₂]_n (CuBT)) from the 5,5′-bistetrazole ligand (H₂BT) to increase efficiency and reduce energy consumption was optimized using the hydrothermal method within 24 h with a ratio of (ligand 3: metal salt 3: solvent 1). To increase the application and ease of separation, magnetite nanoparticles encapsulated in polyvinylpyrrolidone (Fe₃O₄@PVP) were stabilized on the surface of MOF (Fe₃O₄@PVP@CuBT) by sonication and hydrothermal methods. The materials were characterized using various analyses, including FT-IR, ¹H NMR, ¹³C NMR, XRD, TEM, SEM, EDX & mapping, BET-BJH, Zeta, DLS, VSM, and ICP. The composite exhibited a surface area (S_BET) of 33.727 m²/g and an average pore diameter of 9.34 nm. XRD analysis confirmed the successful synthesis of the MOF and the presence of magnetite peaks. ICP analysis determined that Fe₃O₄@PVP@CuBT contains 21.507% Cu and 6.197% Fe. VSM analysis showed that the composite has magnetic properties, with a saturation magnetization (M_s) of 5.19 emu/g, indicating its superparamagnetic behavior and ease of separation with a strong magnet. The catalytic properties of the MOF and its magnetic composite were evaluated in the aza-Michael reaction with different amines. Fe₃O₄@PVP@CuBT (3% W) demonstrated the highest conversion percentage (94%) as a strong and recyclable Lewis acid catalyst under mild conditions in the reaction of 2-vinyl pyridine with aniline.

Here, an environmentally safe structure was developed to stabilize and anchor Ce-Cu alloy nanoparticles on carbon nanotubes, and the synthesis of magnetic nanocatalyst CNT/Fe₃O₄@Ce₃-Cu₂ was studied in the synthesis of dicoumarols and bis-1,3-diethyl thiobarbiturates under stable reaction conditions and ultrasonic irradiation. Our studies showed that magnetic multi-walled carbon nanotubes with porous structures performed well in terms of adsorption of Ce₃–Cu₂ and stabilized the structure of these alloy nanoparticles on magnetic carbon nanotubes, resulting in excellent catalytic activity. It should be noted that ultrasound irradiation causes the alloy electrons of Ce₃–Cu₂ to collide and create a synergistic effect between Ce₃–Cu₂ metals. Our studies proved that the designed magnetic catalyst is recyclable and the high stability of this magnetic bimetallic nanocatalyst provides extensive applications in organic syntheses.

Passion fruit peel was treated with or without phosphoric acid activation followed by direct pyrolysis and staged pyrolysis respectively, to obtain four types of passion fruit peel biochar (PFPB) materials including direct pyrolysis-PFPB (D-PFPB), staged pyrolysis-PFPB (S-PFPB), direct pyrolysis-phosphoric acid activated PFPB (PD-PFPB), and staged pyrolysis-phosphoric acid activated PFPB (PS-PFPB). This study is to screen out the PFPB with the best electrochemical property as the electrode modification material. A series of structural and electrochemical characterizations revealed that PS-PFPB featured the largest defect degree, specific surface area and pore capacity and the best electrochemical property, was then applied to modify the glassy carbon electrode (GCE) after mixed with chitosan (CS), to fabricate the electrochemical sensing electrode PS-PFPB/CS/GCE for the simultaneous detection of hydroquinone (HQ) and catechol (CC). The operating condition was investigated and performance of the fabricated sensing electrode was evaluated. The experimental results indicated that the fabricated sensing electrode had an optimal response signal for simultaneous detection of HQ and CC at pH = 7.4 in phosphate buffer solution, with two linear detection ranges (LDRs) of low concentration (2.0–40.0 µM) and high concentration (40.0-200.0 µM), and limit of detections (LODs) of 0.28, 0.19 µM and 1.39, 1.05 µM for HQ and CC detections in the low and high concentration ranges, respectively. The fabricated sensing electrode also exhibited a good reproducibility, reproducibility and stability as well as good anti-interference ability, and was applied for the simultaneous detection of HQ and CC in real seawater sample successfully by using the standard addition method. This study provides useful reference information for the preparation of novel biochar materials, and their application in electrochemical sensing detections.

The preparation of porous yet mechanically stable centimetric monoliths remains challenging using traditional methods. Herein, hierarchical SBA-15-based porous monoliths, with three levels of porosity (micro- and mesopores from the pores arrangement of the silica structure, and macropores from the replication of polymer beads), were prepared by simple inverse-opal technique. Though the addition of bentonite and proper thermal treatment, solids with specific surface areas above 300 m²/g and resistance toward compression above 50 N were obtained, which is coherent with a use as heterogeneous catalyst supports.

Electrochemical double-layer capacitors (EDLCs) have attracted significant attention because their fast charging/discharging performance, excellent cycle life, and high-power density. Despite these advantages, EDLC still need to overcome their low capacity and improve their fast charging/discharging performance. To achieve high-performance EDLCs, the development of novel active materials with excellent properties is crucial. In this study, reduced-graphyne oxide (rGYO) and biomass-derived activated tofu-based carbon (A-tofu) composites, which exhibited superior performance compared to commercial activated carbon (YP50F), were combined through composite formation (rGYO@A-tofu) and applied as active materials for EDLCs. The rGYO@A-tofu electrode demonstrated excellent performance at both low and high current densities, with a specific capacitance of 280.4 F g^-1 at a current density of 0.2 A g^-1 and 156 F g^-1 at a current density of 20 A g^-1. Additionally, the rGYO@A-tofu electrode exhibits excellent capacitance retention (95.4% after 5,000 cycles at a current density of 10 A g^-1). The excellent performance of the rGYO@A-tofu electrode was attributed to the synergistic effect of the connection between the biomass-derived activated tofu-based carbons through rGYO and the improved electron mobility owing to the unique alkynyl groups in rGYO. Therefore, rGYO@A-tofu is a promising active material for use in EDLCs.

Oil spills pose adverse impact on human health and marine ecosystems, necessitating the development of efficient and sustainable cleanup solutions. Metal–Organic Frameworks (MOFs), as advanced porous materials, have gained significant interest because of their intriguing characteristics like functional versatility, large surface area, and adjustable porosity. Herein, we introduce a hybrid material by incorporating Polyoxometalates (POMs) into MOF-808 via a solvothermal reaction, enhancing its hydrophobicity, stability, and oil absorption capacity. The hybrid material was fabricated onto a cost-effective, widely available, and porous polyurethane (PU) sponge substrate using a simple dip-coating and drying method. The resulting hydrophobic PU@POMOF@PA composite sponge demonstrated an impressive oil absorption capacity of 58.6 gg⁻¹ for vegetable oil at room temperature, and a water contact angle of 132.1°. The composite sponge efficiently separated various oils and organic solvents from water, even under challenging conditions such as high ionic strengths. Remarkably, the composite maintained its performance over 25 recycling cycles, underscoring its durability and reusability. Comprehensive characterization techniques confirmed the material’s structural integrity and enhanced properties. This study highlights a cutting-edge approach to oil spill cleanup, showcasing a scalable and practical solution to mitigate environmental damage while advancing sustainable materials development.

Self-supporting porous carbons containing multiple iron species were synthesized through confined carbonization, alkali etching and final anneal by utilizing varied mesoporous silicas, polymerized aniline and iron chloride as the hard template, carbon/nitrogen and iron precursors, respectively. The duplicated carbons containing multiple iron species have mesoporous structures with large pore diameters, pore volumes and specific surface areas. Consequently, all samples showed excellent electrocatalytic activity toward oxygen reduction reaction (ORR) in 0.1 M KOH via 4-electron pathway. The activity order followed PANI-Fe-HT2(MCF) > PANI-Fe-HT2(MCM-48) ≈ PANI-Fe-HT2(KIT-6) > PANI-Fe-HT2(SBA-15) > PANI-Fe-HT2(MCM-41), suggesting that the three dimensional (3D) interconnected mesoporous structures of hard templates are generally more favorable for fabricating high-performing Fe-N-C materials. The highest onset potential (E_onset) and half-wave potential (E_1/2) obtained for the PANI-Fe-HT2(MCF) were 0.99 and 0.86 V, respectively, which even slightly surpass those of Pt/C, probably shedding light on the additional activity contribution of the unique pore structure duplicated from the MCF. The PANI-Fe-HT2(MCF)-based zinc-air battery (ZAB) delivered impressive power density (116.26 mW cm^-2) and specific capacity (788 mAh g_Zn^-1) as well, completely rivaling the Pt/C-based ZAB. The universal method will hold great promise for exploiting efficient Fe-N-C materials in their practical device applications.

This study presents a facile and effective molten salt strategy to synthesize Mo₂N nanoparticles embedded in N-doped mesoporous carbon using molten salts as templates. The resulting composites had high surface areas and pore volumes. Additionally, the synthesized samples exhibited excellent activity and durability for hydrogen evolution reaction across a wide pH range, with low overpotentials and small Tafel slopes. After 1000 cycles of long-term testing, the electrocatalyst achieved excellent durability. Furthermore, the low cost and simplicity of the proposed synthetic approach make it a promising method for future synthesis of similar transition metal composites.