Journal of Porous Materials最新文献

Volatile organic compounds (VOCs) are primary components of air pollutants that pose a risk to the environment and public health. Adsorption is regarded as one of the most effective and practical strategies for dealing with VOCs contamination. A series of shaped binderless Beta/ZSM-5 composites were produced by a vapor-phase transfer method and dealuminated using a sulfuric acid solution to increase SiO₂/Al₂O₃ ratio after steaming treatment to further increase the hydrophobicity of the samples. The shaped binderless Beta/ZSM-5 composites were characterized with XRD, SEM, TEM, XRF, NMR and N₂ adsorption-desorption. The VOCs adsorption properties of the dealuminated Beta/ZSM-5 mesoporous composites and microporous ZSM-5 zeolites were assessed using dynamic adsorption experiments and temperature-programmed desorption (TPD) under both dry and wet environments. The results revealed that the dealuminated Beta/ZSM-5 composites have larger specific surface area and mesopore volume as well as strong hydrophobicity, and exhibit higher toluene, butyl acetate and o-xylene adsorption capacity than ZSM-5 under either dry or wet environments.

The urgent need for technologies to ensure health standards, as per the Sustainable Development Goals established by the United Nations, has prompted research into addressing human health problems associated with chemical contaminants in air, water, and soil. Heavy metals, particularly arsenic, pose significant health risks, with millions of people worldwide exposed to concentrations exceeding recommended limits. Nanostructured materials, including ordered mesoporous substrates such as SBA-15, have shown promise for arsenic removal due to their high surface area and pore characteristics. This study aimed to synthesize a silica mesoporous material with reduced pore channel length to enhance surface area and active sites, thereby improving arsenic removal efficiency. By exploring various surfactant-to-silica precursor ratios, a suitable value was identified to promote the production of shortened SBA-15 particles. These shortened pore channels facilitated the dispersion of iron oxide nanoparticles (Fe₂O₃) on the SBA-15 surface, resulting in an effective adsorbent that achieved over 95% arsenic removal. The combination of the modified SBA-15 substrate and Fe₂O₃ nanoparticles demonstrated high efficiency in arsenic removal from aqueous effluents, offering a promising solution to address water pollution and associated health risks.

SBA-15-supported Al₂O₃-P₂O₅ with 10 wt% Al₂O₃ and different P₂O₅ mass percentages (10Al₂O₃-xP₂O₅/SBA-15) were prepared by simple impregnation method and used for gas-phase selective O-methylation of catechol to guaiacol with dimethyl carbonate. The 10Al₂O₃-xP₂O₅/SBA-15 catalysts maintained ordered mesoporous structures, but their specific surface areas, pore volumes, and pores decreased with the addition of Al and P oxides. The addition of P₂O₅ decreased the strength of weak acid, but with the P₂O₅ content increasing, the additional pseudo-bridging bonds that are similar to amorphous silica-alumina were formed, which enhanced the acidity of weak acid. Brønsted acid sites introduced by P₂O₅ promoted more acid sites and lower the strength of acid sites. The basic sites increased with the increase of P₂O₅ content. Acidic sites are the key to control the catalytic activity, and basic sites are the key to control the catalytic selectivity. 10Al₂O₃-5P₂O₅/SBA-15 exhibited excellent catalytic activities and high selectivity to guaiacol for the O-methylation of catechol, due to the synergistic effect of acid and base sites.

The separation of oil and water mixtures has become crucial globally due to the frequent incidents of petroleum substances and organic solvents leaking into water and the growing necessity to treat industrial wastes containing oil. Most methods for removing oily pollutants are often time-consuming, costly, and low-efficiency, and they also cause secondary pollution. The absorption method of oily pollutants has been noticed due to its high efficiency, low energy requirement, and simple application. Aerogels are considered one of the most attractive absorbents for separating oil and water mixtures due to their unique characteristics, such as low density, high porosity, and suitable oil absorption capacity. In this research, a superhydrophobic cellulose aerogel was prepared using crystalline cellulose extracted from waste paper, TiO₂, SiO₂ nanoparticles, and vinyltrimethoxysilane by a simple dip-coating method for the first time. It was then utilized to remove oily pollutants and organic solvents from water. XRD, FESEM, EDS, FT-IR, DLS, BET, and water contact angle measurements were employed to identify and characterize the synthesized materials and the modified aerogel. The prepared cellulose aerogel exhibited a water contact angle of 163.39˚ and a sorption capacity ranging from 28.5 to 31.5 g.g^− 1 for various oily pollutants and organic solvents. Additionally, this superhydrophobic aerogel demonstrated excellent reusability and effectively removed emulsified oil droplets in water. This research showed that the aerogel made from waste paper can effectively separate oily pollutants and organic solvents from water.

The porous TiC ceramics with different porosity were fabricated by hot-press sintering using CaO as pore-forming agent, which opened a new field to explore pore ceramics. Then a serious of porous TiC were fabricated and investigated the microstructure, porosity and mechanical properties of pore TiC. The porosity and bulk density of TiC depend on CaO content, which significantly affects the microstructure, mechanical properties and fracture behaviors. With the CaO content increasing, the porosity and pore size of TiC are increased, while the bulk density is decreased. Compressive strength and specific compressive strength exhibit a trend of monotone variation, and the maximum compressive strength is 51.3 MPa when CaO content is 40 vol%. A high porosity condition leads to a loose structure with low load-bearing capacity. As CaO content increases from 40vol% to 55vol%, porosity of TiC increases from 32.9 to 52.6%, and the compressive strength of porous TiC decreases from 51.3 MPa to 9.7 MPa. Additionally, it was concluded that porosity determine the bulk density and strength of porous TiC. However, the thermal conductivity of pore TiC increases with rising of porosity. This is attributed to the total number of pores is decrease owing to CaO agglomeration.

In comparison with traditional mesoporous materials, dendritic mesoporous silica&titania nanospheres (DMSTNs) with three-dimensional central radial pore channels and multiscale pores have larger pore volume, higher specific surface area, and easier accessible surfaces, making them promising carrier platforms for the applications in catalysis, drug delivery, heavy metals adsorption, etc. In this study, DMSTNs have been manufactured by a one-pot co-condensation method using titanium(diisopropoxide)bis(2,4-pentanedionate) (TDA) as the titanium source. Their morphologies and structures have been finely tuned by TDA content, reaction temperature, stirring rate, solvents, and so forth. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have been utilized to directly reveal their differences. Two typical kinds of DMSTNs synthesized at different temperatures have been compared, covering N₂ adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS), Raman spectrum, ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis-DRS), Fourier Transform Infrared spectroscopy (FT-IR), etc. XPS and Raman results testify that the chemical composition and architecture of these DMSTNs resemble those of titanium silicalite-1 (TS-1) zeolite. The hydrogen yield and the corresponding rate of DMSTNs synthesized at 120 ℃ are 3.56 µmol·g^-1 and 0.71 µmol·g^-1·h^-1, being about 2.99 times higher than those of DMSNs that solely own SiO₂ in the skeleton. Nevertheless, DMSTNs synthesized at 70 ℃ possess a 10.08 µmol·g^-1 yield and a 2.04 µmol·g^-1·h^-1 rate, nearly 8.47 times higher than those of DMSNs.

Herein, we report a facile method to fabricate thermo-mechanically reinforced polymer nanocomposite aerogel for oil-field-generated water treatment applications. Polystyrene-graphene (PS-G) aerogel was prepared using solvent crystallization-induced phase separation through flash-freezing route. The fabricated polymer nanocomposite aerogel was characterized using Fourier-Transform Infra-Red spectroscopy (FT-IR), X-ray diffraction (XRD), Differential scanning calorimetry (DSC), Field-Emission Scanning Electron Microscopy (FE-SEM), and Brunauer-Emmet-Teller (BET) surface area, and nano-indentation test. The PS-G nanocomposite aerogel showed 3D-interpenetrating network structures with high specific surface area (~ 300 m²/g) and high porosity. Notably, the PS-G aerogel exhibits a reinforced compression strength of 152 kPa compared to that of PS aerogel (124 kPa). The PS-Graphene aerogel showed T_g value as high as 101.4 ^oC. The PS-G nanocomposite aerogel was found to be a potential absorbent for the rapid removal of oil from produced water samples. Interestingly, the PS-G nanocomposite aerogel exhibited an oil absorption capacity of 50 g/g and reached saturation within 20 min. Furthermore, the aerogel nanocomposite absorbent can be easily regenerated by simple squeezing or washing with methanol and was found to be efficiently recycled up to 10 cycles with only a negligible reduction in oil absorption efficiency.

The nitrogen-doped activated carbon (NAC) with high specific area (3140.76 m²·g^− 1) derived from pomelo peel was prepared using hydrothermal carbonization, nitrogen doping and KOH activation method for the effective removal of Doxycycline (DOX) from aqueous solution. NAC showed exceptional adsorption efficacy for DOX than non-doped activated carbon (AC), which was attributed to the rich N-containing functional groups on the NAC surface and well-developed pore structure. The adsorption equilibrium data of DOX on NAC was fitted well to the Sips isotherm model and the adsorption process was spontaneous, endothermic and randomness-increasing. The Elovich kinetic model could better describe the adsorption process of DOX. The adsorption mechanisms of DOX onto NAC could be attributed to the hydrogen bonding, π-π electron donor-acceptor (EDA) interaction, hydrophobic effect and electrostatic interaction. Besides, the N-doping enhanced the adsorption performance of NAC. The maximum saturated adsorption capacity of NAC was 1559.35 mg·g^− 1 at 298 K, indicating that the NAC could be a promising adsorbent for removing Doxycycline from wastewater.

Combination therapy for cancers can fully utilize each treatment method’s benefits in order to maximize anti-tumor actions and hence produce superior therapeutic outcomes. In this study, HMTNs@PMO@HA composite nanoparticles, a pH/NIR dual-responsive chemo-photothermal platform, were constructed. The hollow mesoporous titanium dioxide nanoparticles (HMTNs) were prepared by silica-protected calcination and alkali etching, and the periodic mesoporous organosilica (PMO) was coated on top of them to improve the biocompatibility, and then modified by hyaluronic acid (HA) to improve the targeting and cellular uptake of the nanoparticles. This chemo-photothermal platform combined the chemotherapeutic drug doxorubicin (DOX) with the photothermal agent indocyanine green (ICG) to investigate their inhibitory effects on breast cancer cells (MCF-7). Drug loading and release experiments revealed that the platform had a high loading rate of doxorubicin and indocyanine green (DOX: 40.21%; ICG: 25.78%), and the cumulative release rate of the drugs increased in an acidic environment. The results of the photothermal effect evaluation in vitro indicated that the nano-platform had a good photothermal effect. Cytotoxicity and apoptosis assays showed that the nanoparticles combined with NIR had a good inhibitory effect on breast cancer cells (cell viability: 27.68%; apoptosis rate: 43.4%). The above results indicated that the combination therapy used by this nano platform provided high therapeutic efficiency for treating tumors and offered a feasible strategy for combining tumor-targeting with chemo-photothermal therapy.

Propylene is an essential chemical feedstock, which needs efficient and stable production technology to meet its increasing industrial demand. In this work, the Pt–Sn/MgAl₂O₄ catalysts fabricated via the incipient wetness impregnation method were used for propane dehydrogenation to propylene (PDH). The effect of Sn on reaction performance was investigated to determine the optimal loading amount. The characterization results from XRD, N₂ physisorption, TEM, H₂-TPR, NH₃-TPD, and TGA elucidated the physicochemical characteristic evolution with varied Sn content in the catalysts. The Pt0.3Sn/MgAl₂O₄ achieved the best propane conversion of 40.9% and propylene selectivity of 82.5% at 600 °C. Sn addition promoted Pt dispersion, enhanced metal-support interactions, and inhibited the side reactions. The MgAl₂O₄ support could suppress the coke formation and maintain propylene selectivity. This work demonstrates the Pt–Sn/MgAl₂O₄ catalysts are effective and durable for PDH to meet propylene demand.