Mesoporous Structure Research Articles

Selective benzene hydroalkylation: Ni/Ni PS/HY catalysts for enhanced cyclohexylbenzene formation

The potential for synthesizing cyclohexylbenzene through one-step hydroalkylation of benzene is significant, but the selectivity is hindered by the deep hydrogenation of benzene to cyclohexane. In this study, Ni-containing phyllosilicate (Ni PS) was incorporated between Ni nanoparticles and zeolite (HY) using the deposition–precipitation technique, thereby creating Ni/Ni PS/HY. A conventional Ni/HY catalyst was also prepared using the impregnation method for comparison. Ni/Ni PS/HY demonstrates outstanding catalytic performance even at a low temperature of 130 °C and a high WHSV of up to 42.21 h−1, achieving a benzene conversion of ∼25 % and a cyclohexylbenzene selectivity of ∼85 %, which remained stable for 300 h. By contrast, the conventional Ni/HY catalyst yields a mere 2.5 % benzene conversion under identical conditions. Comprehensive characterizations and density functional theory (DFT) calculations reveal that Ni PS plays crucial roles in the hydroalkylation of benzene to cyclohexylbenzene. The formation of Ni PS leads to high Ni dispersion, generating more active sites for hydrogenation. Concurrently, the robust interaction between Ni PS and Ni reduces the reactivity of adsorbed H species, impeding the deep hydrogenation of benzene to cyclohexane, while still effectively allowing the formation of cyclohexene. After being adsorbed by the strong acid sites within Ni PS, the intermediate cyclohexene can be smoothly transported through the mesoporous structure of Ni PS to HY for alkylation. All these factors culminate in the exceptional catalytic performance of Ni/Ni-PS/HY.

Structurally Tunable Graphitized Mesoporous Carbon for Enhancing the Accessibility and Durability of Cathode Pt‐Based Catalysts for Proton Exchange Membrane Fuel Cells

Low Pt utilization and intense carbon corrosion of cathode catalysts is a crucial issue for high‐efficiency proton exchange membrane fuel cells due to the highly demanded long‐term durability and less acquisition/application cost. Herein, structurally tunable graphitized mesoporous carbon (GMC) is obtained by direct high‐temperature pyrolysis and in situ‐controlled mesopore formation; the structure‐optimized GMC1300‐1800 exhibits a mesopore size of 7.54 nm and enhanced corrosion resistance. Functionalized GMC1300‐1800 is loaded with small‐sized Pt nanoparticles (NPs) (1.5 nm) uniformly by impregnation method to obtain Pt/GMC1300‐1800 and form an “internal platinum structure” to avoid sulfonic acid groups poisoning as well as ensure O2/proton accessibility. Hence, the electrochemically active surface area (ECSA) of Pt/GMC1300‐1800 reaches 106.1 m2 g−1Pt, while mass activity and specific activity at 0.9 V are 2.1 and 1.4 times those of commercial Pt/C, respectively. Notably, the ECSA decay is less than 17% for both 30 000 cycles’ accelerated durability tests (ADTs) of Pt attenuation and carbon attenuation. Accordingly, the optimized mesoporous structure of GMC1300‐1800 significantly decreases the coverage of sulfonic acid groups on Pt NPs, leading to the highest peak power density in the single‐cell test. Density functional theory calculations demonstrate the synergistic effect between graphitization and mesoporosity on enhancing the accessibility and durability of the catalysts.

Sustainable Banana-Waste-Derived Biosorbent for Congo Red Removal from Aqueous Solutions: Kinetics, Equilibrium, and Breakthrough Studies

This study investigates the adsorption of Congo red (CR) dye from wastewater using banana peel biochar (BPBC) in both batch and fixed-bed column modes. BPBC was characterized using FTIR, SEM, XRD, TGA, and BET analysis, revealing a predominantly mesoporous structure with a surface area of 9.65 m2/g. Batch adsorption experiments evaluated the effectiveness of BPBC in removing CR, investigating the influence of the BPBC dosage, initial CR concentration, and solution pH. Results showed optimal CR removal at pH levels below 4, suggesting a favorable electrostatic interaction between the adsorbent and the dye. Furthermore, a pseudo-first-order kinetic model best described the adsorption process. The Freundlich isotherm provided a better fit compared to the Langmuir and Dubinin–Radushkevich (D-R) models, implying a heterogeneous adsorption surface. The calculated maximum adsorption capacity (Qm) from the Langmuir model was 35.46 mg/g. To assess continuous operation, breakthrough curves were obtained in fixed-bed column experiments with varying bed heights (1–3.6 cm). The results demonstrated efficient CR removal by BPBC, highlighting its potential for wastewater treatment. Finally, this study explored the feasibility of BPBC regeneration and reuse through four adsorption–desorption cycles.

Recent Developments on CO2 Hydrogenation Performance over Structured Zeolites: A Review on Properties, Synthesis, and Characterization

This review focuses on an extensive synopsis of the recent improvements in CO2 hydrogenation over structured zeolites, including their properties, synthesis methods, and characterization. Key features such as bimodal mesoporous structures, surface oxygen vacancies, and the Si/Al ratio are explored for their roles in enhancing catalytic activity. Additionally, the impact of porosity, thermal stability, and structural integrity on the performance of zeolites, as well as their interactions with electrical and plasma environments, are discussed in detail. The synthesis of structured zeolites is analyzed by comparing the advantages and limitations of bottom-up methods, including hard templating, soft templating, and non-templating approaches, to top-down methods, such as dealumination, desilication, and recrystallization. The review addresses the challenges associated with these synthesis techniques, such as pore-induced diffusion limitations, morphological constraints, and maintaining crystal integrity, highlighting the need for innovative solutions and optimization strategies. Advanced characterization techniques are emphasized as essential for understanding the catalytic mechanisms and dynamic behaviors of zeolites, thereby facilitating further research into their efficient and effective use. The study concludes by underscoring the importance of continued research to refine synthesis and characterization methods, which is crucial for optimizing catalytic activity in CO2 hydrogenation. This effort is important for achieving selective catalysis and is paramount to the global initiative to reduce carbon emissions and address climate change.

Ordering Bimetallic Cu‐Pd Catalysts onto Orderly Mesoporous SrTiO3‐Crystal Nanotubular Networks for Efficient Carbon Dioxide Photoreduction

Artificial photosynthesis of fuels has garnered significant attention, with SrTiO3 emerging as a potential candidate for photocatalysis due to its exceptional physicochemical properties. However, selectively converting CO2 into fuels with desired reaction products remains a grand challenge. Herein, we design an updated method via an aging strategy based on the electrospinning technique to synthesize a single‐crystalline Al‐doped SrTiO3 nanotubular networks with self‐assembled orderly mesopores, further modified by Cu‐Pd alloy. It exhibits both high crystallinity and superior cross‐linked mesoporous structures, effectively facilitating charge carrier transfer, photon utilization, and mass transfer, with a remarkable enhancement from 0.025 mmol·h‐1·m‐2 to 1.090 mmol·h‐1·m‐2 in the CO production rate. Meanwhile, the ordered arrangement of Cu and Pd atoms on the (111) surface can promote the rate‐determining step (*CO2 to *COOH), which is also responsible for its good activity. The presence of CuO in the reaction confers a significant advantage for CO desorption, leading to a remarkable CO selectivity of 95.54%. This work highlights new insights into developing advanced heterogeneous photocatalysts.

Kinetic study of adsorption and photocatalytic degradation of methylene blue dye using TiO2 nanoparticles with activated carbon

Abstract Activated carbon (AC) exhibits limited adsorption capacity for pollutants. Conversely, titanium dioxide (TiO2) demonstrates excellent photocatalytic performance, making it a popular choice for pollutant removal. This study investigates the removal of methylene blue (MB) dye from wastewater using AC, TiO2@AC-2, and TiO2@AC-10 samples via adsorption and photocatalysis. The Energy Dispersive analysis of X-rays (EDAX) has confirmed the presence of Ti, C and O in the prepared samples without any impurities. All the diffraction peaks in X-ray diffractograms indicated the presence of pure anatase TiO2 (tetragonal phase) with no evidence of any other phase. Fourier transform infrared spectroscopy (FTIR) analysis identified a peak around 545 cm⁻¹ in the TiO2@AC-2 sample, indicative of O-Ti-O stretching vibrations. This peak shifted to 602 cm⁻¹ in the TiO2@AC-10 sample. Raman spectroscopy confirmed the presence of carbon (D and G bands) at 1310-1347 cm⁻¹ and 1582-1597 cm⁻¹. Additionally, characteristic Raman active bands for anatase TiO2 were observed at 154 cm⁻¹ (Eg), 204 cm⁻¹ (Eg), 398 cm⁻¹ (B1g), 508 cm⁻¹ (A1g), and 628 cm⁻¹ (Eg). N2 adsorption-desorption isotherms revealed a mesoporous structure for all samples (AC, TiO2@AC-2, and TiO2@AC-10) with hysteresis loops, indicating pores ranging from 2 nm to 50 nm in diameter. Reflectance spectra of TiO2@AC-2 and TiO2@AC-10 displayed absorption edges at 368 nm and 385 nm, respectively, corresponding to a direct band gap of approximately 3.22 eV. Subsequently, these prepared samples were effectively employed for the removal of methylene blue (MB) dye from wastewater utilizing both adsorption and photocatalysis method. Under dark conditions, 20 mg/L doses of TiO2@AC-2 and TiO2@AC-10 resulted in 60% and 36% dye adsorption within 60 minutes respectively. In the presence of UV radiation, the degradation of dye was observed to be 74% and 95% by TiO2@AC-2 and TiO2@AC-10 respectively. This observation indicates that TiO2 nanoparticles along with AC leads to enhanced photocatalytic activity. The Langmuir-Hinshelwood model reveals lower rate constants for AC compared to the composite samples. This is likely because AC lacks inherent catalytic activity, requiring UV light to trigger adsorption. Conversely, TiO2@AC-10 exhibits the highest rate constants (K1 = 24.25 × 10-3 min⁻¹ and K2 = 82.71 × 10-3 min⁻¹), aligning with its higher TiO2 content confirmed by EDAX analysis. This suggests a significantly faster photocatalytic rate and superior degradation efficiency, even at a low sample concentration (20 mg/L).

Postsynthetic modification of yttria‐stabilized zirconia aerogels with silica coatings for enhanced thermal stability

AbstractMaintaining high surface area and porosity at high temperatures is important when considering aerogels for use in thermal management systems. The mesoporous structure of aerogels results in extremely low thermal conductivity, making them lightweight, high performance insulating materials. Maintaining these properties requires innovative routes to suppress sintering and pore collapse as use temperatures rise. The current work aims to improve the pore structure stability of yttria‐stabilized zirconia aerogels by the addition of a SiO2 coating. The functionalization of surface hydroxyl groups by the addition of SiO2 is hypothesized to mitigate condensation reactions, which are a driving force for shrinkage and pore structure collapse. Zirconia aerogels with 0, 10, and 30 mol% yttria (YO1.5) additions were coated in a tetraethyl orthosilicate (TEOS) solution and exposed to temperatures up to 1200°C. Crystal structure, pore structure, and aerogel morphology were investigated to understand changes in aerogel thermal stability. The SiO2 coating exhibited a greater influence on pore stability over yttria concentration, with specific surface area of the coated aerogels being twice that of the uncoated aerogels up to 1000°C. However, the presence of the SiO2 coating promoted rapid sintering and densification at 1200°C, establishing an upper use temperature for SiO2 and a need to develop other coating chemistries.

The impact of a TiO2/r-GO composite material on the performance of electron transport electrodes of dye sensitized solar cells.

In dye sensitized solar cells, the role of the electron transport layer is crucial because it makes it easier for photo-generated electrons to get from the dye to the external circuit. In DSSCs, the utilization of TiO2 is likely to be given preference in the production of electron transport electrodes due to its notable characteristics such as its expansive surface area, porosity, and capacity to scatter light. Nevertheless, the presence of heterogeneity within the mesoporous structure increases the likelihood of TiO2 aggregation, which subsequently diminishes the beneficial impact of TiO2 on the performance of DSSCs. In this context, reduced graphene oxide (r-GO) is introduced as an additive into the TiO2 network during the preparation of TiO2/reduced graphene oxide (r-GO) composites. The integration of r-GO with TiO2 has been recognized as a promising approach to enhance electron transport and electron lifespan, owing to remarkable qualities exhibited by r-GO. The present investigation involved the synthesis of a composite material including titanium dioxide/reduced graphene oxide (TiO2/r-GO) through the utilization of the co-precipitation technique. Following this, the generated TiO2/r-GO composite material and pure TiO2 were deposited on FTO through electrophoretic deposition to obtain an electron transport electrode of a dye sensitized solar cell. It should be noted that when r-GO was combined with TiO2, the performance of DSSCs improved notably compared to pure TiO2. As a result, the findings of this work have significant implications for the advancement of the TiO2/r-GO composite deposited through electrophoretic deposition. The power conversion efficiency reached 6.64% with the addition of r-GO in the metal oxide electron transport electrode. The obtained findings align with the outcomes of electrochemical impedance investigations in which the electrode constructed with TiO2/r-GO exhibits reduced electron transport resistance (RCt) at the anode/dye/electrolyte interface, as well as lower overall resistance (Rtotal) in comparison to TiO2-based DSSCs. These advancements have the potential to be employed in commercial DSSC manufacturing.

Improved Synthesis of Cu2O NPs and Ascorbic Acid-Modified Derivatives for Adsorption of Brilliant Cresyl Blue: Surface and Reusability Studies

This study addresses the critical need for efficient and recyclable photocatalysts for water treatment applications by presenting a novel approach for the synthesis and characterization of copper (I) oxide (Cu2O) nanoparticles modified with ascorbic acid (Cu2O/AA). The motivation for this research stems from the increasing concern about environmental pollution caused by organic pollutants, such as Brilliant Cresyl Blue (BCB), and the necessity for sustainable solutions to mitigate this issue. Through comprehensive characterization techniques including Ultraviolet–Visible spectroscopy (UV-Vis), Fourier Transform Infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), zeta potential measurements, and Brunauer–Emmett–Teller (BET) analysis, we demonstrate a significant modification to the electronic structure, enhancing the photocatalytic activity of Cu2O/AA. BET analysis revealed a mesoporous structure with a specific surface area of 2.7247 m2/g for Cu2O/AA, further emphasizing its potential for enhanced catalytic performance. The photocatalytic degradation studies showcased remarkable efficiency improvements, with degradation coefficients of 30.8% and 73.12% for Cu2O NPs and Cu2O/AA NC, respectively, within a 120 min timeframe. Additionally, recyclability experiments indicated sustained efficiency over five consecutive cycles, with both catalysts retaining crystalline integrity. These findings underscore the promising potential of Cu2O/AA nanoparticles as highly efficient and recyclable photocatalysts for the degradation of organic pollutants, offering superior performance compared to pure Cu2O NPs and addressing the pressing need for sustainable water treatment solutions.

Synthesis and characterization of hydroxyapatite nanoparticles from calcium hydroxide fouled with gases evolved from smokestack of glass industry

In glass industry, the evolved gases and fumes from burning the gas fuel absorbed in calcium hydroxide to minimize the pollution of environment. After a period of time, the calcium hydroxide fouled with sulphate and carbonate as action of the absorbed SO3 and CO2 gases. Based on our interest to treatment the solid waste materials, this study intended to convert the obtained waste of calcium hydroxide fouled with gases to valuable products. Firstly, this waste was treated with water, caustic soda and acids. The results confirmed the conversion of waste to pure calcium sulfate by treatment with 6 v/v% sulfuric acid. Secondly, the obtained calcium sulfate was reacted with ammonium dihydrogen phosphate solution for preparation of calcium hydroxyapatite (HAp) nanoparticles. The produced HAp sample was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and N2 adsorption measurements. The obtained findings confirmed that the HAp can be produced after calcination at 700 °C, nanorods-like of sizes ranged from 11 to 15 nm and with main surface functional groups of hydroxyapatite. TGA and DTA data indicated that HAp is thermally stable up to 700 °C. Also, the obtained HAp has Ca/P molar ratio of 1.60 and exhibited high total surface area of 146 m2/g with mesoporous structure which make this material can be used in medical and water purification applications.

Magnetron-Sputtered Long-Term Superhydrophilic Thin Films for Use in Solid-State Cooling Devices

Pulse-magnetron-sputtered long-term superhydrophilic coatings have been synthesized to functionalize the surfaces of solid-state cooling devices, e.g., electrocaloric heat pumps, where not only a complete wetting of the surface by a fluid is intended, but also fast wetting and dewetting processes are required. The coatings consist of a (Ti,Si)O2 outer layer that provides lasting hydrophilicity thanks to the mesoporous structure, followed by an intermediate WO3 film that enables the reactivation of the wettability through visible light irradiation, and a W underlayer which can work as a top electrode of the electrocaloric components thanks to its suitable electrical and thermal conductivity properties. Process parameter optimization for each layer of the stack as well as the influence of the microstructure and composition on the wetting properties are presented. Finally, water contact angle measurements, surface energy evaluations, and a contact line dynamics assessment of evaporating drops on the coatings demonstrate that their enhanced wetting performance is attributed not only to their intrinsic hydrophilic nature but also to their porous microstructure, which promotes wicking and spreading at the nanometric scale.

Effects of porous structure and oxygen functionalities on electrochemical synthesis of hydrogen peroxide on ordered mesoporous carbon

Two-electron oxygen reduction reaction (2e− ORR) is a promising alternative to energy-intensive anthraquinone process for hydrogen peroxide (H2O2) production. Metal-free nanocarbon materials have garnered intensive attention as highly prospective electrocatalysts for H2O2 production, and an in-depth understanding of their porous structure and active sites have become a critical scientific challenge. The present research investigates a range of porous carbon catalysts, including non-porous, microporous, and mesoporous structures, to elucidate the impacts of porous structures on 2e− ORR activity. The results highlighted the superiority of mesoporous carbon over other porous materials, demonstrating remarkable H2O2 selectivity. Furthermore, integration of X-ray photoelectron spectroscopy (XPS) data analysis with electrochemical assessment results unravels the moderate surface oxygen content is the key to increase 2e− ORR activity. These results not only highlight the intricate interplay between pore structure and oxygen content in determining catalytic selectivity, but also enable the design of carbon catalysts for specific electrochemical reactions.

Efficient ozone decomposition in high humidity environments using novel iron-doped OMS-2-loaded activated carbon material.

This study effectively addresses the rapid deactivation of manganese-based catalysts in humid environments during ozone decomposition by introducing iron-doped manganese oxide octahedral molecular sieve (Fe-OMS-2) catalysts supported on activated carbon (AC). By optimizing the doping ratio of Fe-OMS-2, the Fe-OMS-20.5/AC catalyst achieves nearly 100% ozone decomposition efficiency across a wide range of relative humidity levels (0 to 60%), even at elevated air flow rates of 800 L·g-1·h-1, outperforming standalone AC, Fe-OMS-2, or a simple mixture of OMS-2 and AC. The Fe-OMS-20.5/AC catalyst features a porous surface and a mesoporous structure, providing a substantial specific surface area that facilitates the uniform distribution of the Fe-OMS-2 active phase on the AC surface. The incorporation of Fe3+ ions enhances electron transfer between valence state transitions of Mn, thereby improving the catalyst's efficiency in ozone decomposition. Additionally, the AC component protects catalytic sites and enhances the catalyst's humidity resistance. In conclusion, this research presents a novel strategy for developing highly efficient and cost-effective ozone decomposition catalysts that enhance dehumidification, significantly contributing to industrial ozone treatment technologies and advancing environmental protection.

Interlayer Potassium Single-Atom-Coordinated g-C3N4 for Significantly Boosted Visible Light Photocatalytic H2 Production.

In recent years, graphitic carbon nitride (g-C3N4) has attracted considerable attention because it includes earth-abundant carbon and nitrogen elements and exhibits good chemical and thermal stability owing to the strong covalent interaction in its conjugated layer structure. However, bulk g-C3N4 has some disadvantages of low specific surface area, poor light absorption, rapid recombination of photogenerated charge carriers, and insufficient active sites, which hinder its practical applications. In this study, we design and synthesize potassium single-atom (K SAs)-doped g-C3N4 porous nanosheets (CM-KX, where X represents the mass of KHP added) via supramolecular self-assembling and chemical cross-linking copolymerization strategies. The results show that the utilization of supramolecules as precursors can produce g-C3N4 nanosheets with reduced thickness, increased surface area, and abundant mesopores. In addition, the intercalation of K atoms within the g-C3N4 nitrogen pots through the formation of K-N bonds results in the reduction of the band gap and expansion of the visible-light absorption range. The optimized K-doped CM-K12 nanosheets achieve a specific surface area of 127 m2 g-1, which is 11.4 times larger than that of the pristine g-C3N4 nanosheets. Furthermore, the optimal CM-K12 sample exhibits the maximum H2 production rate of 127.78 μmol h-1 under visible light (λ ≥ 420 nm), which is nearly 23 times higher than that of bare g-C3N4. This significant improvement of photocatalytic activity is attributed to the synergistic effects of the mesoporous structure and K SAs doping, which effectively increase the specific surface area, improve the visible-light absorption capacity, and facilitate the separation and transfer of photogenerated electron-hole pairs. Besides, the optimal sample shows good chemical stability for 20 h in the recycling experiments. Density functional theory calculations confirm that the introduction of K SAs significantly boosts the adsorption energy for water and decreases the activation energy barrier for the reduction of water to hydrogen.

Ternary heterostructure-driven photoinduced electron-hole separation enhanced oxidative stress for triple-negative breast cancer therapy

Zinc oxide nanoparticles (ZnO NPs) stand as among the most significant metal oxide nanoparticles in trigger the formation of reactive oxygen species (ROS) and induce apoptosis. Nevertheless, the utilization of ZnO NPs has been limited by the shallowness of short-wavelength light and the constrained production of ROS. To overcome these limitations, a strategy involves achieving a red shift towards the near-infrared (NIR) light spectrum, promoting the separation and restraining the recombination of electron-hole (e−-h+) pairs. Herein, the hybrid plasmonic system Au@ZnO (AZ) with graphene quantum dots (GQDs) doping (AZG) nano heterostructures is rationally designed for optimal NIR-driven cancer treatment. Significantly, a multifold increase in ROS generation can be achieved through the following creative initiatives: (i) plasmonic Au nanorods expands the photocatalytic capabilities of AZG into the NIR domain, offering a foundation for NIR-induced ROS generation for clinical utilization; (ii) elaborate design of mesoporous core-shell AZ structures facilitates the redistribution of electron-hole pairs; (iii) the incorporation GQDs in mesoporous structure could efficiently restrain the recombination of the e−-h+ pairs; (iv) Modification of hyaluronic acid (HA) can enhance CD44 receptor mediated targeted triple-negative breast cancer (TNBC). In addition, the introduced Au NRs present as catalysts for enhancing photothermal therapy (PTT), effectively inducing apoptosis in tumor cells. The resulting HA-modified AZG (AZGH) exhibits efficient hot electron injection and e−-h+ separation, affording unparalleled convenience for ROS production and enabling NIR-induced PDT for the cancer treanment. As a result, our well-designed mesoporous core-shell AZGH hybrid as photosensitizers can exhibit excellent PDT efficacy.

Adsorption of thorium (IV) from aqueous solutions using mesoporous TiO2: Kinetics, isotherm and thermodynamics

Thorium is considered as a promising resource for the production of nuclear power, with its abundance in the Earth's crust offering potential for sustainable energy generation to fulfill upcoming energy needs. As a fertile material, thorium has the capability to be converted into fissile uranium-233, which is essential for sustaining nuclear chain reactions. Therefore, the extraction of thorium from the Earth's crust is imperative for its utilization as fuel in nuclear reactors. This study presents the synthesis of titanium dioxide with a mesoporous structure using the solvothermal method for extracting Th(IV) from aqueous solutions. Batch adsorption experiments were carried out to evaluate the impact of solution pH, adsorption kinetics, adsorbent dosage, initial Th(IV) concentration, and temperature. The adsorption process is influenced by the pH, showing a maximum adsorption capacity of 101.4 mg per gram of mesoporous TiO2 adsorbent (MTA) at an initial Th(IV) concentration of 400 mg L−1 at pH 4.0. Results indicate a significant correlation with the pseudo-second-order and Freundlich adsorption isotherm models. Temperature-dependent investigations revealed that the adsorption of Th(IV) is spontaneous at room temperature and increases with higher temperatures (endothermic process). Moreover, the study highlights the rapid kinetics of Th(IV) adsorption by MTA, making it a favorable choice for upscaling the extraction process of Th(IV). In conclusion, the results suggest MTA as a promising adsorbent for the removal of Th(IV) from aqueous solutions.

Hollow multi-shelled structure engineering of organosilica for efficient and selective uranium extraction from seawater

Uranium extraction from seawater is critical for the development of nuclear energy, but the progress is still seriously limited by the performance and cost of current adsorbents. Herein, a convenient and general co-condensation process is designed to prepare amidoximated multi-shelled hollow mesoporous organosilica adsorbent (AO-HMO), which exhibits a high uranium extraction capacity of 862.07 mg·g−1 in uranium-spiked simulated seawater and 9.67 mg·g−1 in natural seawater. The run-through mesoporous structure and multi-shelled surface provide fast diffusion channels and more active sites for uranium adsorption. Moreover, AO-HMO exhibits a long service life due to its robust structure, maintaining an ideal adsorption capacity over 10 adsorption-desorption cycles. Coupled with the synthesis-cost advantage, AO-HMO will surely show great application potential in uranium extraction form seawater in future.

Catalytic combustion of toluene over highly dispersed Pt NPs embedded in porous TiO2 via in situ pyrolysis of MOFs

In this work, a series of x wt% Pt@TiO2 (x = 0.18, 0.42, and 0.84) catalysts with highly dispersed Pt nanoparticles (NPs) are synthesized via pyrolysis method using Ti-based metal-organic frameworks (MOFs) as precursors. Physicochemical properties of the catalysts are characterized by a number of analytical techniques. It is shown that all samples possess mesoporous structure with surface area of 59–75.6 m2/g, thus can suppress the aggregation of Pt NPs, and enhance toluene adsorption and diffusion. The 0.84 wt% Pt@TiO2 catalyst exhibits the best catalytic performance for toluene oxidation (T90% =150 °C at space velocity = 20,000 mL/ (g h)), which is attributed to the higher surface area, abundant adsorbed oxygen and Pt0 species, and strong interaction between Pt NPs and TiO2. In addition, the possible reaction mechanism of toluene oxidation is proposed based on in situ DRIFTS technique.

Trypsin Encapsulation in the Zeolitic Imidazolate Framework for Low-Molecular Weight Protein Analysis with High Selectivity and Efficiency.

Low-molecular weight proteins (LWPs) are important sources of biological information in biomarkers, signaling molecules, and pathology. However, the separation and analysis of LWPs in complex biological samples are challenging, mainly due to their low abundance and the complex sample pretreatment procedure. Herein, trypsin modified by poly(acrylic acid) (PAA) was encapsulated by a zeolitic imidazolate framework (ZIF-L). Mesopores were formed on the ZIF-L with the introduction of PAA. An alternative strategy for separation and pretreatment of LWPs was developed based on the prepared ZIF-L-encapsulated trypsin with adjustable pore size. The mesoporous structure of the prepared materials selectively excluded high-molecular weight proteins from the reaction system, allowing LWPs to enter the pores and react with the internal trypsin, resulting in an improved separation efficiency. The hydrophobicity of the ZIF-L simplified the digestion process by inducing significant structural changes in substrate proteins. In addition, the enzymatic activity was significantly enhanced by the developed encapsulation method that maintained the enzyme conformation, allowed low mass transfer resistance, and possessed a high enzyme-to-substrate ratio. As a result, the ZIF-L-encapsulated trypsin can achieve highly selective separation, valid denaturation, and efficient digestion of LWPs in a short time by simply mixing with substrate proteins, greatly simplifying the separation and pretreatment process of the traditional hydrolysis method. The prepared materials and the developed strategy demonstrated an excellent size-selective assay performance in model protein mixtures, showing great potential in the application of proteomics analysis.

Dealloying Strategies for Mesoporous AuCu Nanoparticles: Impact on Internal Metallic Structure and Electrocatalytic Performance

Tailoring the surface structure of the mesoporous metal catalysts is pivotal for influencing both the catalytic activity and selectivity. Through the dealloying of bimetallic alloys, surface modification is achieved by dissolving unstable components, thereby forming a multitude of catalytically active sites. In this study, highly enhanced electrocatalysts are fabricated via chemical etching of mesoporous AuCu alloy nanoparticles prepared through the self‐assembly of micelles. The presence of large mesoporosity (>10 nm) with rich defect sites on the surface, along with the synergistic effect arising from the AuCu bimetallic alloy, effectively boosts electrocatalytic performance for the ethanol oxidation reaction. This strategy demonstrates a promising strategy to further enhance the catalytic performance of Au‐based mesoporous nanoparticles by eliminating the unstable metal component and refining the mesoporous structure with an abundance of various active sites.