Journal of Porous Materials最新文献

The hydrogel (HGs) was synthesized via free radical polymerization using Sodium alginate-g-poly(hydroxyethyl acrylamide-co–N isopropylacrylamide-co-2-Acrylamido-2-methylpropane sulfonic acid), with reactant concentrations optimized via the Taguchi method. Furthermore, a magnetic hydrogel (MHGs) was prepared by coprecipitating Fe²⁺ and Fe³⁺ ions. The study characterized the hydrogel (HGs) and the composite (MHGs) using FTIR, FESEM, TEM, VSM, XRD, TGA, AFM, and BET. The study also focused on removing Lead ions (Pb²⁺) from aqueous solutions. The maximum adsorption capacity was higher at 250.7 mg/g in 35 ^OC, and the kinetics of adsorption were found to comply with the pseudo-second order model. Moreover, the lead ions (Pb²⁺) uptake followed the Freundlich and Temkin isotherms. The investigation of the (Pb²⁺) removal at different temperatures (5,15,25, and 35 °C) showed that the adsorption process is basically of a physical type. The calculations were made for the Gibbs free energy, enthalpy, entropy, and the equilibrium constant. For this study, we chose the Response Surface Methodology RSM in conjunction with Analysis of Variance ANOVA to explore the Pb²⁺ adsorption as a function of temperature, Pb²⁺ concentration, and acidity. The results showed that with increasing pH and temperature, the adsorption efficiency increases, which follows the endothermic nature of the process. The efficiency of Pb²⁺ removal was checked after washing the adsorbent with hydrochloric acid, and the results were quite encouraging, even after four washes.

The introduction of mesopores is essential to mitigate diffusion limitations in microporous architectures, particularly for zeolites with one-dimensional micropore channels. In this study, we synthesized hierarchical ZSM-48 zeolites with tunable crystallinity and acidity through utilizing dodecyl trimethylammonium chloride (DTAC) as a mesoporous template and combined with gradient acid treatment. Unlike conventional post-synthetic methods that compromise framework integrity, this approach successfully preserved the microporous structure while introducing mesopores, and effectively removing non-framework aluminum to optimal acid distribution. Compared to conventional samples, hierarchical ZSM-48 zeolites exhibit higher catalytic performance during the isomerization of n-decane. As the acid-treated time was extended, the crystallinity of the hierarchical ZSM-48 zeolite gradually increased, while the strong Brønsted/Lewis (B/L) acid ratio initially increased and then decreased. The highly crystallized hierarchical ZSM-48 zeolite with a high B/L ratio was able to balance the synergistic effects between the mesoporous structure and acidity, achieving the highest isomer selectivity. This work establishes a green and scalable route for designing shape-selective bifunctional catalysts, emphasizing crystallinity-acidity interplay in balancing activity and selectivity.

Micro tomography emerges as a dependable, efficient, and non-destructive technique compared to traditional methods for assessing micro architectural characteristics in scaffolds. Chitosan, gelatin, and monetite [dicalcium phosphate anhydrous, DCPA] containing scaffolds with tailored structures and properties have great potential for bone repair and regeneration. Scaffolds were prepared from the viscous slurry containing chitosan, gelatin, and synthesized monetite nanoparticles using the freeze-drying method. The prepared scaffold showed significantly high interconnected porosity with pore size varying between 90–390 µm. Incorporating the monetite particles led to an increase in the stiffness diminishing the degree of hydrophilic sites in the polymer matrix resulting in the reduction in the average pore size, porosity, swelling capacity, and biodegradation rate of the fabricated composite scaffolds. The micro architectural features were examined, with a focus on quantifying various parameters such as pore size, shape, orientation, interconnectivity, and fractal analysis. All the scaffolds exhibited a favorable porosity range between 77 to 88%, a degree of pore anisotropy varying between 1.5 to 2, and a fractal dimension varying between 2.4 to 2.8, making them suitable for the applications in bone tissue engineering (BTE). The scaffolds possessed notable macro porosity alongside favorable pore architecture and interconnectivity. The quantification of diverse parameters yielded promising outcomes, highlighting micro tomography's efficacy as a tool for studying and quantifying pore characteristics in BTE scaffolds.

By employing a room temperature batch method, we successfully synthesized single crystals of Na⁺ ion-exchanged, binary ion (Mn²⁺ and Na⁺) exchanged, and Mn²⁺ ion exchanged zeolite A, enabling detailed structural analysis via single-crystal synchrotron X-ray diffraction. The structures of these fully dehydrated crystals: Na⁺ ion exchanged zeolite A (Crystal 1), 0.08 M Na⁺:0.02 M Mn²⁺ ion exchanged zeolite A (Crystal 2), 0.05 M Mn²⁺: 0.05 M Na⁺ ion exchanged zeolite A (Crystal 3), and Mn²⁺ ion exchanged zeolite A (Crystal 4) were determined by single-crystal synchrotron X-ray diffraction techniques. Measurements were conducted in the cubic space group Pm-(bar{3})m at 100(1) K, with the structures refined to the final error indices R₁/wR₂ of 0.0486/0.1565, 0.0600/0.1625, 0.0549/0.1443, and 0.0768/0.2077 (for F_o > 4σ(F_o)) for crystals 1, 2, 3, and 4, respectively. No dealumination was observed in these structures. In the fully Na⁺ ion-exchanged structure (Crystal 1), Na⁺ ions fully occupy the 6-ring positions, which, while demonstrating complete ion occupancy, potentially limits functionality due to blocked 8-ring windows. In contrast, the 0.08 M Na⁺:0.02 M Mn²⁺ ion-exchanged crystal (Crystal 2) showed an ideal distribution of ions, with evenly filled 6-rings and open 8-ring windows. The structural analysis emphasizes the critical role of ion distribution within zeolite A, suggesting structural implications that may inform future material design for ion exchange or separation application.

This study presents the synthesis of a hierarchical flower-like ZnCo₂O₄/MoS₂ nanocomposite integrated with reduced graphene oxide (rGO) nanosheets using a simple hydrothermal method. The structural, morphological, and compositional properties of the material are systematically analysed. Electrochemical characterization in a three-electrode configuration with 1.0 M KOH demonstrates that ZnCo₂O₄/MoS₂@rGO achieves a high specific capacitance of 1764 F/g at 1 A/g, with excellent cycling stability, retaining 97% of its capacitance after 10,000 cycles. When assembled into an asymmetric supercapacitor (ZnCo₂O₄/MoS₂@rGO//AC), the device delivers a maximum energy density of 45.27 Wh/kg at a power density of 3326 W/kg, while maintaining 96% capacitance retention over 10,000 cycles. The enhanced electrochemical performance is attributed to the synergistic effects of ZnCo₂O₄, MoS₂ and rGO, which collectively improve charge transport and electrochemical activity. These results highlight the potential of ZnCo₂O₄/MoS₂@rGO as a high-performance electrode material for next-generation supercapacitors.

Porous carbon (PC) derived from coal tar pitch (CTP) is a suitable electrode material for energy storage devices due to its high surface area, high conductivity, cost-effectiveness, and eco-friendliness. Phosphorous-doping (P-doping) may augment the physicochemical and electrochemical characteristics of PC. Herein, the phosphorus-doped porous carbon material was synthesized by a one-step carbonization-activation method using coal tar pitch as a carbon precursor and zinc phytate as a hard template and a phosphorus source. The phosphorus-doped mesoporous carbon (PMC-900) delivered a specific capacitance of 277 Fg^− 1 at a current density of 0.1 A g^− 1 and excellent cycle performance with no capacitance decay after 10,000 cycles at 5 A g^− 1 in 6 M KOH aqueous electrolyte. Furthermore, it delivered a high energy density of 13.5 Whkg^− 1 at a power density of 43.8 Wkg^− 1. The proposed study indicates promising application prospects of the CTP-derived mesoporous carbon in supercapacitors application.

Developing a robust Pt catalyst with lower Pt loading is highly desired for propane dehydrogenation (PDH) process. SnS-1 zeolite with Sn incorporation to the silicalite-1 (S-1) zeolite framework was synthesized and applied as support for constructing PtSnS-1 catalyst. Pt was introduced into the heteroatom-containing zeolite crystals via ion exchange, which enabled Pt to exist as atomic species anchored at the Sn-containing zeolite framework. Characterizations of the catalyst in STEM, HRTEM and XPS reveal that, the PtSnS-1 catalyst constructed in this way has the active structure that allowed the catalyst to be much active and catalytic stable. The PtSnS-1 catalyst with 0.03 wt% Pt content delivered as high as 191.3 mol·g_Pt⁻¹·h^− 1 of propylene yielding rate at the start of the reaction with a much lower deactivation rate constant 0.002 h^− 1 during 231 hours’ long-term reaction at 550 ^oC.

The overuse of fossil fuels has led to their degradation, encouraging the search for alternative energy sources that are abundant, affordable, and environmentally friendly. Many researchers are exploring water splitting as an effective method for producing green energy to address this challenge. In this report, we present the electrocatalytic properties of a cost-effective carbon-metal composite derived from biomass and synthesized at 750 °C using cobalt (Co) and molybdenum (Mo) precursors for the hydrogen evolution reaction (HER) in alkaline electrolytes at various pH levels. Physical characterizations, including X-ray diffraction (XRD), Raman spectroscopy, and field-emission scanning electron microscopy (FE-SEM), confirm the formation of a nanoporous carbon-metal composite (MOCoC/750, where MO represents molybdenum oxide, and Co is cobalt, both anchored to carbon catalyst C). Electrochemical characterization demonstrates the impact of different alkaline pH levels (8.2, 9.5, 11.2, 12.6, and 14) on the electrocatalytic HER activity of MOCoC/750. For HER, the as-synthesized catalyst requires a low overpotential of -0.172 V to achieve the benchmark current density of -10 mA/cm² in an electrolyte at pH 14. In contrast, it requires an overpotential of -0.400 V to achieve the same current density in a near-neutral electrolyte (pH 8.2), making it a highly effective catalyst compared to others in similar conditions.

This study presents the development of a high-performance poly(o-toluidine)/graphene oxide (POT/GO) nanocomposite sensor for efficient H₂S gas detection. The nanocomposite was synthesized using a facile in-situ polymerization method, ensuring uniform graphene oxide dispersion within the poly(o-toluidine) matrix. The structural and morphological characteristics of the materials were analyzed using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and UV-visible spectroscopy. The POT/GO sensor demonstrated a threefold improvement in sensitivity when compared to pure POT, with a maximum response of 99% at 100 ppm H₂S. The sensor operates entirely at room temperature, with a rapid response of 90 s and recovery of 85 s times, and high selectivity against interfering gases. The findings underscore the promise of the POT/GO nanocomposite as a reliable and energy-efficient sensing material suitable for practical applications.

A series of binder-free MCM-22 zeolite catalysts were synthesized within 60 h using a vapor-phase transport (VPT) method, employing MCM-22 precursors prepared via hydrothermal crystallization as seeds. The synthesized zeolites were systematically investigated by using X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier-transform infrared spectra (FT-IR), ²⁷Al magic angle spinning nuclear magnetic resonance (MAS NMR), N₂ adsorption–desorption, temperature-programmed desorption of ammonia (NH₃-TPD), and X-ray fluorescence (XRF) techniques. The results demonstrated that the addition of precursor seeds (PS) with crystallization time of 36, 48, 60, and 72 h significantly modified the crystal morphologies and improved pore structures and acidic properties of the final products compared to which was synthesized with conventional calcined seed. Specifically, the binder-free MCM-22, PS of which was crystallized for 48 h, exhibited the largest specific surface area, pore volume, and the highest acid site density, leading to superior activity and selectivity in the alkylation of benzene with benzyl alcohol. Furthermore, XRD, FT-IR, SEM, and thermogravimetric analysis (TGA) of PS provided insights into the possible mechanism for the highly efficient synthesis of binder-free MCM-22 zeolites. This work provided a novel and efficient approach for the synthesis of binder-free MCM-22 zeolites, showing potential applications in catalyst industry.