Journal of Porous Materials最新文献

The CuO-mesoporous silicon oxide nanocomposites are widely used in the adsorption and degradation of environmental pollutants, attributing to the effective photogenerated electrons and holes and high specific surface area of mesoporous silicon oxide. In this papers, Cu(NO₃)₂ was introduced during the assembly process of mesoporous silicon oxide to prepare CuO/MCM-41 nanocomposites by one-step method, which significantly simplified the preparation process compared to post-synthesis transplantation method. The prepared CuO/MCM-41 nanocomposites was characterized by Brunauer–Emmett–Teller (BET), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscope (FE-SEM), Energy-dispersive X-ray Spectroscopy (EDS) and X-ray Diffraction (XRD). CuO/MCM-41 nanocomposites had excellent degradation effect under UV irradiation of 12W on different structures dyes, such as Methylene Blue(MB), Direct Fast Scarlet 4BS, Direct Yellow 27 and Reactive Turquoise Blue KN-G. It was demonstrated that the kinetic studies of photocatalytic degradation of MB were fitted well with the first-order kinetic model. The degradation of MB retained 97% after five cycles reusing of the catalyst. The results indicated that CuO/MCM-41 nanocomposites could be used as an effective photocatalyst for the degradation of different types of dyes in wastewater.

A novel hybrid of silica-gelatin modified by bovine serum albumin-folate was designed in the current study as a pH-sensitive drug carrier. The fluorouracil was loaded by entrapment efficiency of 70%. The nanocarrier was evaluated in terms of pH-sensitive release behavior in simulated acidic condition of cancer tissue (pH = 5.6), and the normal physiological condition of the body (pH = 7.4) for 96 h. In vitro, drug release from nanocarriers indicated a partial rapid release in the early times (34 and 21% after 12 h in acidic and neutral media), which was followed by a sustained and gradual release profile up to 65% in acidic medium, and 42% in natural medium after 96 h, confirming the pH-responsive behavior of the developed nanocarrier. The Higuchi model adequately described the release data. The results of kinetic model indicated that the release process is mainly controlled through diffusion mechanism. The toxicity study showed low toxicity of drug-free carriers against normal human dermal fibroblast cells (HDF) and human ovarian cancer cells (OVCAR-3). These outcomes support the proper function of the designed hybrid nanocarrier in targeted drug delivery.

This study not only explores the fabrication of rare zeolites from waste pumice and examines the impact of aging on their porosity and adsorbate uptake but also provides practical insights for waste management and agricultural applications. The use of organic templates was avoided in the synthesis due to their high cost and pollution associated with their calcination. Potassium-exchanged gonnardite (K-Gon) and perlialite were hydrothermally synthesized using KOH. Interestingly, we found that increasing the magnetic stirring duration during synthesis had a significant impact on the products’ surface area and pore volume, leading to an increase from 39 m²/g to 182 m²/g and from 0.11 cm³/g to 0.30 cm³/g, respectively. This improvement resulted in an increased adsorbate uptake at higher pressures. At shorter stirring times, potassium-exchanged gonnardite zeolite with tetragonal symmetry was the most prevalent phase, which differs from the orthorhombic symmetry of Na-rich gonnardites. Additionally, we observed that the product content of perlialite (hexagonal symmetry) increased with longer stirring durations while K⁺ ions decreased. This suggests that increased stirring time can increase the disorderliness of extra framework particles, as seen in perlialite, as opposed to K-Gon. Longer stirring time produces other zeolites with slightly less K but improved textural properties, which can potentially accommodate more water. It is also useful for agricultural purposes, such as keeping soils moist and decontaminated, and as adsorbents for greenhouses’ air conditioning.

Macroporous lithium manganese iron phosphate/carbon (LiFe_0.9Mn_0.1PO₄/C) has been successfully synthesized via a sol-gel process accompanied by phase separation. Poly (ethylene oxide) (PEO) acts as a phase separation inducer, while polyvinylpyrrolidone (PVP) synergistically regulates the morphology of the gel skeleton and serves as a reducing agent. Propylene oxide (PO) works as a proton scavenger to initiate the homogeneous gelation and modify the macrostructure. An appropriate amount of PEO, PVP and PO led to the formation of xerogel monoliths characterized by a three-dimensional co-continuous skeleton and interconnected macropores. The amorphous xerogel upon heat treatment at 400 °C for 2 h under a N₂ atmosphere, formed carbon-coated LiFe_0.9Mn_0.1PO₄/C crystals with excellent crystallinity and uniform elemental distribution. The resultant macroporous LFMP/C has a discharge capacity of 113.43 mA h g^− 1 at 0.1 C, with a first coulombic efficiency of 90.1% and excellent capacity recovery rate after high-rate tests.

When it comes to owning pets, pet odor is a major concern for many individuals. Ammonia (NH₃) and hydrogen sulfide (H₂S) are the primary odor components that have negative effects on human life. Therefore, there is an urgent need to develop a deodorizing material with high NH₃ and H₂S adsorption capacity. In this study, Resorcinol-formaldehyde (RF) aerogels containing amine groups (RF-Mx) were prepared using the sol-gel method and atmospheric pressure drying technique. Melamine was used as a modifier. The specific surface area of the modified aerogel was 119 m²/g with an average pore size of 12 nm when the melamine addition was 20%. The adsorption capacity of RF-M20 for odor was the highest (NH₃: 593.8 mg/g, H₂S: 640 mg/g), which was significantly superior to the unmodified sample. In addition, the adsorption capacity of RF-M20 for H₂S exceeded that of commercial activated carbon. The results concluded that the introduction of amine groups and the higher microporous specific surface area benefited the chemical and physical adsorption of gases, effectively improving the adsorbent’s capacity to capture NH₃ and H₂S. The preparation method is not only efficient in enhancing the odor adsorption capacity but also simple and cost-effective to operate, showing promising potential for industrial applications.

The effect of post-treatment of TS-1 zeolite by tetrapropyl ammonium hydroxide aqueous solution under hydrothermal condition was studied in this work. The characterizations of structure, morphology and composition demonstrated that an open and hierarchical porous structure was generated in TS-1 zeolite after the post-treatment. With increasing the alkalinity of TPAOH solution, the hierarchical porosity and hydrophobicity increased and the framework Ti content decreased in the post-treated TS-1 zeolite. Both the pristine and post-treated TS-1 zeolites were employed as the catalysts for the reaction of phenol hydroxylation. It was found that the post-treated TS-1 zeolite possessed a higher catalytic performance than the pristine TS-1 zeolite. The larger the alkalinity of the post-treatment solution was, the higher the catalytic performance of the post-treated TS-1 zeolite was; however, a too high alkalinity of the post-treatment solution also led to the decline in the catalytic performance. This could be a result of the combined influences of the hierarchical porosity, hydrophobicity and framework Ti content on the catalytic performance. The higher levels of hierarchical porosity and hydrophobicity promoted but the lower level of framework Ti content inhibited the catalytic performance of TS-1 zeolite. Accordingly, the controlling to the alkalinity of TPAOH solution for the post-treatment was very important in respect of the catalytic performance of TS-1 zeolite.

Designing inexpensive and efficient absorbent materials derived from waste is still challenging but of great significance to environmental safety and resource protection. Herein, the modified Hummers’ waste liquid was used as a precursor reactant to synthesize the three types of manganese oxides via a chemical precipitation method. The components, microstructure, and adsorption capacities of the manganese oxides for heavy metal ions were investigated in detail. The results show the manganese oxides have porous structures and different crystal phases as manganese dioxide (I-MO), manganese oxide hydroxide (II-MO), and trimanganese tetraoxide (III-MO), respectively. Compared with II-MO and III-MO, I-MO has a specific surface area and pore volume of 142.27 m²·g⁻¹ and 0.622 cm³·g⁻¹, respectively. The experiments reveal that Ι-MO exhibits better adsorption performance of heavy metal ions than II-MO and III-MO. At 298 K, the maximum adsorption amounts of Pb²⁺, Cd²⁺, and Cu²⁺ on the Ι-MO are 304.15, 175.37, and 74.48 mg·g⁻¹, respectively. The experimental findings closely match both the pseudo-second-order model and the Langmuir model. Moreover, I-MO exhibits a satisfactory adsorption capacity for heavy metal ions even after six repetitive cycles. All of these show that I-MO is a cost-effective adsorbent for heavy metal ions elimination in water.

Recently, element doping has become an effective strategy to improve the gas sensing properties of In₂O₃-based materials by adjusting their electronic structures. Herein, Pt-modified In₂O₃ nanobundles, composed of nanofibers, were prepared using a simple hydrothermal method. The dispersion of Pt nanoparticles on the In₂O₃ surface was achieved through an in-situ reduction process. High-resolution TEM images reveal that the In₂O₃ nanofibers possess an average diameter of 30 nm. Brunauer-Emmett-Teller(BET) indicates that the Pt modification can increase the specific surface area. XPS indicates that the introduction of Platinum(Pt) nanoparticles can both increase the oxygen vacancy ratio, and facilitate to trap the electrons, as a result of improving the sensing performance. The gas sensing tests demonstrate that the Pt decorated In₂O₃ nanobundles show excellent sensitivity (5.12 of 100 ppm) and selectivity towards formaldehyde at the optimized temperature of 180 °C. This shows that the decoration of Pt nanoparticles can lower the optimized working temperature and shorten the response/recovery times, of which the enhanced performance can be attributed to electronic and chemical sensitization.

In order to decouple structural parameters of silica aerogels like particle size, pore size and fractal dimension on the one hand from aerogel properties such as aerogel density, thermal and mechanical characteristics on the other hand, the structural properties were varied in a wide range. It has been a challenging task to find synthesis parameters still resulting in gels, but also covering a wide property space. For this goal, three synthesis routes, based on the classical tetraalkoxysilane route, were chosen. The structural properties of the silica aerogels produced cover more than two orders of magnitude in particle and pore sizes, whereas the variation of density and porosity is limited by the Si-content of the silica source. Due to physical limitations, not all combinations of pore size correlated to an aerogel density are possible, leading to a gap for small densities and small pores as well as for high densities and large pores. For increasing particle sizes, the structure generation mechanism seems to alter from particle generation and subsequent cluster formation to phase separation. Along with that, the mechanical stiffness drops down for larger structures (pores and particles). For the mechanical and thermal properties, only the solid thermal conductivity scales roughly with the Young’s modulus, thus giving the opportunity of decoupling mechanical and thermal conductivity at ambient pressure from each other.

Electrochemical energy technologies are crucial for a sustainable future, promising to transform energy generation, storage and use with improved efficiency and environmental responsibility. In this study, Fe was integrated into the MCM-48 framework to create a modified mesoporous structure to be used as electrodes for electrochemical storage applications. The materials were thoroughly characterized using various spectroscopic and non-spectroscopic techniques, including XRD, XPS, UV-Vis (DRS), FT-IR, N₂ adsorption-desorption analysis, SEM with EDX, ICP-OES, TEM, TGA and DSC. Cyclic voltammetry and galvanometric charge-discharge studies revealed that the Fe-MCM-48 sample with Si: Fe molar ratio of 20 (Fe-MCM-48 (20)) exhibited pseudocapacitive behaviour, showcasing higher capacitance value of up to 787 F g^− 1 at a current density of 1 A g^− 1. The findings undeniably indicate that Fe-MCM-48 (20) holds promise as a highly effective electrode material for advancing energy storage technologies like supercapacitors.