Journal of Porous Materials最新文献

Dynamic emissivity control is a transformative feature of MXene-based materials, enabling advanced thermal camouflage solutions for next-generation technologies. This review explores the latest advancements in the design and development of MXene composites, focusing on porous structures, phase-change material integration, and scalable thin-film fabrication techniques. These approaches enhance MXene’s ability to reduce infrared emissivity, improve thermal insulation, and adapt to dynamic environments. Applications in emerging fields such as 5G/6G communication devices, infrared stealth technology, and aerospace systems are highlighted, showcasing their broad potential. Addressing challenges like oxidation sensitivity, mechanical durability, and scalability, this review provides critical insights into the future directions of MXene-based thermal camouflage materials, bridging the gap between current research and real-world applications.

The commercial RuO₂ used for electrochemical oxygen evolution reaction (OER) is more expensive. Also nickel foam and glassy carbon substrates were very expensive for the fabrication of working electrodes that ignore/minimize the practical applications. Hence we used low-cost and most abundant elements for the fabrication of working electrode with graphite substrate effectively. Likewise, there is no photocatalytic study available on various pollutants by the same materials leads to limit the photocatalytic application in real-time wastewater treatment. In this study, simple synthesis of reduced graphene oxide (rGO), poly-1-aminoanthraquinone (PAAQ), and layered double hydroxide (LDH) supported MoO₂–NiCo₂O₄ photo-electrocatalytic materials by the hydrothermal process has done and extensively investigated for physicochemical properties. The optical band gap energy of rGO@MoO₂/NiCo₂O₄ NCs (RMNCO) was found to be 2.33 eV, which implies that it has higher electrical conductivity comparatively. As a BET result, the highest surface area observed for RMNCO composite due to the strong interaction between the interlayer structure of rGO and MoO₂/NiCo₂O₄ particles, it indicates the well binding and lowest interparticle distance. The better OER performance has observed in RMNCO due to high surface area accomplished and also low Tafel slope with overpotential values of 71 mV dec⁻¹ and 327 mV respectively. The photocatalytic degradation study was conducted against Methylene blue (MB), Rhodamine B (RhB) and Acetaminophen (AP) drug under various parameters respectively. The highest degradation efficiency was calculated to be 91.30, 97.37 and 95.62% and it obeyed the pseudo-first-order kinetic model. Also, the antibacterial activity was investigated against gram-positive, gram-negative bacteria and the results showed the highest significant activity. In addition to that, degraded dye solution was utilized to conduct phytotoxicity study to grow mung bean for examining the effects on toxicity. The entire results showed that synthesized photo/electrocatalysts are outstanding candidates for OER, photocatalytic remediation and antibacterial applications etc.

The sol-gel method was employed to synthesize three-dimensional mesoporous Fe-KIT-6 and KIT-6. These materials were investigated for their potential in controlled drug delivery applications, with ibuprofen used as a model drug. Both Fe-KIT-6 and KIT-6 exhibit large pore volumes, narrow pore size distributions, and high surface areas, making them promising candidates for drug adsorption. The introduction of iron into the KIT-6 structure significantly enhanced its drug sorption capacity, with the materials showing an increased ability to adsorb ibuprofen as the iron content increased. Moreover, the release of ibuprofen was more efficient from iron-modified KIT-6, with materials containing iron exhibiting slower and more controlled drug release profiles. These results suggest that Fe-KIT-6 has potential for use in sustained-release drug delivery systems.

Spherical hydroxyapatite (SHAP) has been widely concerned because of its non-toxicity, biocompatibility and unique adsorption capacity. We optimized the synthesis of SHAP using spherical calcium carbonate (CaCO₃) as a template to provide reference for its efficient preparation and application. The optimal synthesis conditions of CaCO₃ are initial salt concentration 0.4 M, PVP concentration 1.0 g/L, stirring 60 min with 700 rpm under 35 °C. Under the optimal conditions, the SEM morphology of SHAP is characterized by spherical particles of uneven surface with a uniform particle size distribution (7.402 μm, D₅₀), porous characteristics and large specific surface area (55.85 m²/g). In addition, SHAP has a high degree of matching with JCPDS no. 09-0432, has a good HAP crystal form, and has high crystal purity. The microstructure and uniform size of SHAP are the basis of its excellent performance, and the above performance parameters of the products in this study are comparable to or even better than some natural HAP and HAP synthesized using different strategies.

Integrating different molecular sieves facilitates to intensify the advantages of each single species but weaken their deficiencies in applications. The main goal of the present work is to align SAPO-44 and SAPO-11 as a potential composite catalyst for hydroisomerization of normal alkanes. In the present work, microparticles of SAPO-44 were used as seed into the SAPO-11 synthesis gel to synthesize SAPO-44/11 composite molecular sieves. The ratio of SAPO-44 to SAPO-11 in the prepared composites was modulated by changing the dose of SAPO-44 seed. The obtained composites have been characterized by XRD, SEM, N₂ adsorption/desorption and NH₃-TPD. The characterizations demonstrated that the crystalline grains of SAPO-44 and SAPO-11 were tightly integrated. Their amount of acid site, as well as specific surface area, exhibits a compromise of that of SAPO-11 and SAPO-44. More strong acid sites and larger surface areas were observed with the increasing content of SAPO-44. Based on the composite molecular sieves, correspondent Pt/SAPO-44/11 bifunctional catalysts were prepared and applied in hydroisomerization of n-hexane. Expectedly, they exhibited superior conversions and yields, attributed to the optimal pore structure and surface acidity of the composites.

CHA Zeolites are currently considered as the most effective catalysts to meet the increasingly stringent emission requirements of diesel vehicles. Herein, the synthesis of SSZ-13 zeolites(CHA topology) using ZSM-5 (MFI topology) with various SiO₂/Al₂O₃ ratios as parent zeolites were investigated in the presence of N,N,N, trimethtyl-1-adamantammonium hydroxide (TMAdaOH). The crystallization processes of three different strategies, that is, high silica ZSM-5 with additional Al source(HSZ + Al), completely zeolite to zeolite(CZTZ) transformation and low silica ZSM-5 with additional Si source(LSZ + Si) were compared. The results show that pure SSZ-13 zeolites with high crystallinity can be synthesized at 160 °C for only 6 h by CZTZ strategy. While for the HSZ + Al and LSZ + Si synthesis systems, the complete transformation from MFI to CHA can even be shortened to 4.5 h at 160 °C, suggesting the promoting effect of additional Al- or Si- source for MFI-CHA transformation. The rapid MFI-CHA transformation may be related to fast disintegration of parent ZSM-5 under the promotion of TMAda⁺ template. Meanwhile, the five-membered rings predominating in the MFI framework rapidly disassembled and rearranged into favorable double six-membered ring and CHA cage composite building units, thus facilitate the rapid formation the CHA framework. Additionally, the resultant samples, after Cu²⁺ exchange, showed superior catalytic activity and hydrothermal stability for the selective catalytic reduction of NOx with NH₃. The operation temperature window (NOx conversion > 90%) of HSZ-4.5 h, CZTZ-6.0 h and LSZ-4.5 h samples were all about 200 ∼ 500 °C. Among three samples, the HSZ-4.5 h presents best low-temperature catalytic activity, while CZTZ-6.0 h and LSZ-4.5 h samples show more superior hydrothermal stability.

This study presents a novel cobalt-based catalyst, iron-doped calcium cobalt oxide (Ca₃Co_2−xFeₓO₆, with x ranging from 0 to 0.3) for the reduction of 4-nitrophenol with NaBH₄ in aqueous solutions. The catalyst was synthesized using a sol–gel method, and then examined for the structure and catalytic performance. Based on FTIR analysis, the optimal synthesis conditions were an annealing temperature of 1000 °C for 10 h, resulting in high purity and crystallinity. Scanning electron microscopy (SEM) analysis showed increased particle sizes with higher iron content. X-ray diffraction (XRD) analysis confirmed the phase purity of the samples and an average crystallite size of 21.6 ± 0.2 nm. Brunauer–Emmett–Teller (BET) equation analysis of nitrogen physisorption at 77 K revealed that iron doping significantly influenced the surface area and porosity of Ca₃Co_2−xFeₓO₆, with an optimal doping level (x = 0.1) maximizing these properties, while higher concentrations led to a decline due to potential pore blockage or densification. These nitrogen physisorption results correlated well with the catalytic activity, as the Ca₃Co_1.9Fe_0.1O₆ composition exhibited the highest reaction rate for reducing 4-nitrophenol, with optimal performance achieved at a pH of 8. Reusability tests demonstrated that the catalyst remained relatively stable over 5 reuse cycles. This research provides valuable insights into the synthesis, structure, and catalytic performance of iron-doped calcium cobalt oxide materials, which have potential applications in environmental remediation and energy-related processes.

Alkyl naphthalene is a synthetic lubricant known for its excellent lubricating properties, including high thermal stability, good viscosity, and oxidation resistance. In this research, the performance of several solid acid catalysts, such as Y zeolite, ZSM-5, MCM-22 and AlMCM-41, was investigated in the alkylation reaction of naphthalene with tetradecene. The catalytic materials were characterized by ICP, BET, N₂ adsorption–desorption isotherms and Py-IR. The experimental findings revealed that Y zeolites showed great potential for the preparation of monoalkyl naphthalene. Notably, Na⁺ ions exhibit a poisoning effect on the acidity of zeolites, particularly in Y zeolites. To investigate this issue, Y zeolites with different Na contents were prepared by an ion exchange method, followed by evaluation and characterization. The results indicated that the catalytic activity of Y zeolites with high Na content was poor. With the decrease of Na content, the catalytic performance of the catalyst was obviously improved, but the selectivity for monoalkyl naphthalene gradually decreased.

The new low-cost, simple and compact experimental system for characterization of porous materials by quasi-equilibrated temperature-programmed desorption and adsorption (QE-TPDA) based on the miniature microprocessor-controlled thermal conductivity sensor Sensirion STC31 has been described in detail. The performance of the new system has been tested in QE-TPDA measurements of nonane for high-silica zeolites Y and ZSM-5, as well as for a series of ordered mesoporous silicas SBA-15. Although very good qualitative agreement of the QE-TPDA profiles measured in the new system with those observed in a standard one was found, slightly lower saturation sorption capacities based on the new profiles were obtained. The pores size distributions (PSDs) calculated from the new nonane QE-TPDA profiles for SBA-15 silicas showed very good agreement with those obtained from N₂ adsorption isotherms using the NLDFT method. An excellent correlation between the pore size values based on both sets of PSDs was found. The new system was also applied in the QE-TPDA of water for selected metal-organic frameworks (MOFs). The QE-TPDA profiles of water observed for two fumarate containing MOFs Al-fum (aka Basolite A520) and MIL-88 A were consistent with the adsorption-desorption isotherms obtained in a standard manometric apparatus. Hydrothermal stability tests of these MOFs, based on prolonged water QE-TPDA measurements, revealed the onset of structure degradation of Al-fum at 350 °C and at 250 °C for MIL-88 A.

This study investigates the effects of sequential alkaline-acid treatments on commercial ferrierite zeolite (Si/Al = 10) using different concentrations of NaOH (0.2 and 0.35 M) and temperatures (80 and 100 ºC), while maintaining a fixed concentration of oxalic acid (0.9 M). These zeolites were then evaluated for their textural properties and acidity in the cracking of n-hexane and ultra-high molecular weight polyethylene (UHMWPE). Chemical and textural properties were characterized by X-ray diffraction (XRD), energy dispersive X-ray (EDX) analyses, nitrogen adsorption–desorption using BET, t-plot and BJH methods, transmission electron microscopy (TEM), thermal analyses (TG/DTG), Fourier transform infrared spectroscopy (FT-IR), and ammonia temperature-programmed desorption (NH₃-TPD). Alkaline treatments caused Si leaching, reducing crystallinity and microporosity, while increasing mesoporosity and external surface area. Subsequent acid treatments restored crystallinity and microporosity by removing amorphous species and preserving mesoporosity. More severe alkaline treatment conditions (0.35 M and 100 ºC) generated more mesopores but significantly reduced microporosity and acidity, compromising the shape selectivity and active catalytic sites of ferrierite zeolite. Thus, the zeolite treated with 0.2 M NaOH and 0.9 M oxalic acid at 80 ºC exhibited the best balance between micro-mesoporosity and acidity, resulting in higher catalytic activity in the cracking of n-hexane and UHMWPE.