Journal of Porous Materials最新文献

Hollow silica nanoparticles have attracted significant attention for biomedical applications owing to their high surface area and excellent chemical stability. However, their practical utilization has been limited by the lack of intrinsic signal transduction capability, which hinders real-time monitoring and tracking in biological systems. In this study, we report the synthesis of carbon quantum dot–incorporated hollow silica nanomaterials using carbon nanospheres as hard templates, followed by in situ generation of carbon quantum dots (CQDs) within the silica matrix. Transmission electron microscopy revealed that the resulting hollow silica possessed a uniform spherical morphology with an average diameter of 165.9 nm and a silica shell thickness of approximately 45 nm. X-ray diffraction confirmed the amorphous nature of the silica framework with a characteristic broad peak at 2θ ≈ 22°. Nitrogen adsorption–desorption analysis indicated a high specific surface area of 520.76 m².g⁻¹, a pore volume of 0.505 cm³.g⁻¹, and a pore diameter of 1.5 nm. Using ibuprofen as a model drug, the CQDs-incorporated nanosilica exhibited a drug-loading efficiency of 34.72%. Photoluminescence and diffuse reflectance spectroscopy demonstrated strong green emission under suitable excitation with an estimated optical band gap of 4.41 eV. Furthermore, cytotoxicity evaluation using L929 cells showed a high survival rate of 98.5% at a concentration of 62.5 µg.mL⁻¹, confirming the excellent biocompatibility of the material. This study highlights the development of an integrated nanostructure in which carbon quantum dots are synthesized in situ within the hollow silica framework, enabling a fluorescent and biocompatible nanocarrier platform with strong potential for future drug delivery applications.

Driven by the ever-increasing demand for efficient adsorbents for removing pollutants from wastewater, β-cyclodextrin functionalized Fe₃O₄/Activated carbon nanocomposites have been synthesized using the co-precipitation method. The crystallite size was around 6 nm, which agrees with the particle size (6.5 nm) calculated from TEM images. Fe, C and O in the prepared β-cyclodextrin functionalized Fe₃O₄/Activated carbon nanocomposites were confirmed through X-ray photoelectron spectroscopy. The prepared materials show strong magnetic behaviour with saturation magnetization of 25 emu per gram, enabling easy manipulation using an external magnetic field. Adsorption studies have been carried out to understand the effect of pH, contact time, adsorbent doses, salt, and dye concentration to understand the adsorption behaviour with respect to Brilliant Green (BG), Congo red (CR), Malachite green (MG). Isotherm plots confirm monolayer adsorption for MG and multilayer adsorption for BG and CR. The optimum pH for BG, MG, and CR removal is 8, 9, and 9, respectively, with removal efficiencies of 230, 31, and 30 mg/g. Given the findings, we report a readily synthesized nanocomposite, which is an economical, efficient, and suitable alternative adsorbent for the removal of both cationic and anionic dyes from contaminated water sources.

The present investigation employed a post-impregnation technique to evaluate the sorptive capacity of the synthesized KIT-6 surface for drug loading from an aqueous solution. Silica KIT-6 was selected as the model adsorbent, with juglone utilized as the model drug for studying its adsorption and release behaviour. The drug loading process was conducted under standard conditions. The materials were characterized both prior to and following drug loading using various techniques, including FTIR, BET analysis, TGA, FESEM-EDX, HRTEM, WA-XRD, and LA-XRD. The solubility and release characteristics of the loaded materials were systematically assessed. Notably, juglone exhibited an entrapment efficiency of 95% in KIT-. 6 and 58% in amine-functionalized KIT-6. Subsequent loading of JUG onto both KIT-6 and amine-functionalized KIT-6 resulted in further decreases in surface area (176 m²/g), pore volume (0.20 cm³/g), and a decrement in the pore size dissemination to smaller diameters (4.6 nm). Amine-functionalized KIT-6 micro-spheres were found to show a significantly slower drug release rate 20 ± 0.43 than pure KIT-6, which should facilitate drug delivery control over a longer time period. The KIT-6 carrier demonstrated superior drug loading capacity and dissolution profile, indicating its potential to enhance juglone bioavailability. This study presents newly developed formulations that incorporate juglone into KIT-6 and amine-functionalized KIT-6, highlighting their potential as effective delivery systems for juglone. These formulations offer enhanced drug bioavailability and improved safety profiles, suggesting their potent role in drug delivery applications.

The incorporation of reduced graphene oxide (rGO) markedly enhances the electrical conductivity, mechanical robustness, and interfacial charge transport characteristics of transition metal sulfides. Owing to their synergistic nanoscale interactions, rGO-integrated metal sulfide composites have emerged as versatile materials for high-performance energy storage and conversion devices. In the present study, a porous reduced graphene oxide/manganese cobalt sulphide (rGO@MnCo₂S₄) hybrid electrode was successfully synthesized through a facile hydrothermal approach. This design strategy aims to improve both the charge storage capacity and long-term cycling stability for supercapacitor applications. Electrochemical evaluation demonstrates that the pristine MCS and rGO@MCS electrodes exhibit specific capacitances of 277 F g⁻¹ and 472 F g⁻¹, respectively, at a current density of 1 A g⁻¹. Moreover, the MCS electrode retains 89% of its initial capacitance after 10,000 cycles, while the rGO@MCS electrode maintains a remarkable 97% retention under identical testing conditions. An asymmetric supercapacitor device assembled using MnCo₂S₄ as the positive electrode and rGO as the negative electrode delivers a maximum energy density of 60 Wh kg⁻¹ at a power density of 850 W kg⁻¹. These findings affirm the superior electrochemical performance and structural stability of the rGO@MCS hybrid, underscoring its strong potential for next-generation high-energy-density supercapacitor applications.

This study successfully prepared a Pd Complex immobilized on the surface of Fe₃O₄ magnetic nanoparticles through a simple and cost-effective process. Detailed characterization was performed using FTIR, XRD, TGA, SEM, EDS, ICP, and VSM techniques. The Fe₃O₄/APTES/CC/GA-Pd catalyst was tested for its effectiveness in the cyanation of aryl halides and the selective synthesis of tetrazoles under varying experimental conditions, including adjustments to catalyst quantities, solvent types, and reaction temperatures. Its notable advantages include ease of synthesis, faster reaction rates, and low catalyst loading requirements. The nanocatalyst was efficiently recovered with an external magnet and reused multiple times without substantial loss of catalytic activity. The heterogeneity of Fe₃O₄/APTES/CC/GA-Pd was further analyzed through hot filtration experiments.

In this study, the Knoevenagel condensation reaction between vanillin and malononitrile was studied using a heterogeneous catalyst such as MCM-41 with a to nominal nickel loadings of 10.2 wt%, under microwave heating. Vanillin, a lignin-derived compound, was used as a model substrate due to its renewable origin and potential for the synthesis of high value-added products. The effects of temperature, amount of catalyst, nickel content and heating method on product yield and selectivity were evaluated. The results show that the best reaction conditions were achieved at 100 °C with 40 mg of catalyst, reaching a conversion and selectivity close to 99% in only 90 min using microwaves. Additionally, it was observed that increasing the nickel loading enhanced the catalytic activity, promoting the deprotonation of malononitrile and favoring the formation of the desired product. The Ni/MCM-41(10) catalyst showed high stability and reusability, maintaining its activity after five reaction cycles with a slight decrease in yield. Furthermore, the methodology was successfully extended to other biomass-derived aldehydes, such as furfural and piperonal, confirming the versatility of the catalytic system and its suitability for sustainable syntheses. This work highlights the combination of heterogeneous catalysts and microwave heating as an efficient and environmentally friendly strategy in green chemistry.

This work investigates the effect of the Si/Sn molar ratio on the physicochemical and catalytic properties of Sn-KIT-6 catalysts during fructose conversion. Sn-KIT-6 mesoporous catalysts were prepared using a hydrothermal sol-gel method, which involved the hydrolysis of tetraethylorthosilicate (TEOS) and tin chloride pentahydrate (SnCl₄·5H₂O) with Pluronic P123 as a surfactant at 35 °C, followed by subsequent calcination at 550 °C. Catalysts with different Si/Sn molar ratios (80, 60, and 40) were synthesized and characterized by SAXRD, TEM, SEM, N₂ physisorption, UV-Vis-DRS, FT-IR of adsorbed pivalonitrile, XPS, and MP-AES. The results confirmed the typical cubic structure of the KIT-6 (Ia3d) material, specific areas between 715 and 746 m²/g, pore diameters reaching 6–8 nm, and pore volume of ∼1.2 cm³/g. The Sn-KIT-6 samples exhibited a significant proportion of tetrahedral tin species that are linked to acid sites. Sn-KIT-6(60) and Sn-KIT-6(40) samples also present small amounts of polymeric tin oxide nanoparticles. Increasing the tin content in the KIT-6 material enhances its acidic properties, which are essential for performing fructose dehydration reactions. In particular, the Sn-KIT-6 catalyst (40) exhibited a higher number of acid sites, leading to increased fructose conversion and selectivity towards HMF. A kinetic model, based on a biphasic system in batch experiments, accurately describes the experimental data.

Volatile organic compounds (VOCs) are common pollutants that are highly volatile and toxic. Adsorption technology has been proven to be an effective method for reducing VOCs emissions. In this work, three porous hyper-crosslinked polymers (HCPs) were successfully prepared and systematically characterized. pBGly-TPA, pBP-TPA, and pBBP-TPA exhibit high specific surface areas as well as excellent hydrophobicity. Dynamic adsorption studies show that these materials have good adsorption capacity for toluene, n-hexane, and cyclohexane. Among them, pBBP-TPA demonstrates the most significant adsorption performance (323.3 mg/g for toluene, 118.2 mg/g for n-hexane, and 161.6 mg/g for cyclohexane). The adsorption kinetics fitted both the Boltzmann and Yoon-Nelson models, suggesting minimal mass transfer resistance in fixed-bed configurations. Notably, pBBP-TPA retained most of its initial adsorption capacity over four consecutive adsorption-desorption cycles and maintained excellent toluene adsorption performance, even in humid environments, making it a promising adsorbent for VOCs removal.

Diffusion limitations in microporous ZSM-5 zeolites hinder the efficient aromatization of light naphtha into valuable BTX (benzene, toluene, xylenes). In this work, we report the development of a mesostructured bimetallic catalyst through controlled alkaline desilication of ZSM-5 (Z5), followed by the incorporation of 2 wt% La and 1 wt% Zn via wet impregnation. The desilicated zeolite (Z5-AT) exhibited enhanced mesoporosity, improving molecular diffusion and boosting BTX yield from 24 wt% (Z5) to 49 wt%. Further metal modification significantly enhanced performance, with the optimized 2%La-1%Zn/Z5-AT catalyst achieving a BTX yield of 72.7 wt% at 550 °C in a fixed-bed down-flow reactor. Zn incorporation enhances the Lewis-to-Brønsted acid site (L/B) ratio, which accelerates dehydrogenation activity and promotes higher BTX formation. Textural and acidity characterizations confirmed uniform metal dispersion, improved surface area, and a favorable increase in L/B ratio. In-situ pyridine-FTIR and NH₃-TPD analyses revealed synergistic effects between La and Zn, promoting dehydrogenation, acidity tuning, and coke suppression. These results demonstrate the effectiveness of mesostructured bimetallic ZSM-5 in enhancing light naphtha aromatization, with high aromatic selectivity and improved stability.

Graphical Abstract

The alternative text for this image may have been generated using AI.